OPT 325 Dispensing Optics II Lecture PDF - University of Cape Coast

DISPENSING OPTICS II OPT-325 DR CHARLES DARKO-TAKYI DEPARTMENT OF OPTOMETRY AND VISION SCIENCE UNIVERSITY OF CAPE COAST  INTRODUCTION Dispensing optics is a branch of eye care tha...

DISPENSING OPTICS II OPT-325 DR CHARLES DARKO-TAKYI DEPARTMENT OF OPTOMETRY AND VISION SCIENCE UNIVERSITY OF CAPE COAST  INTRODUCTION Dispensing optics is a branch of eye care that primarily deals with: the supply of spectacles (a lens and a frame) to clients and offering advice on spectacles-related issues to clients Primary responsibility of Dispensing optician/ optical technician However, it is important for the optometrist to have in-depth knowledge in dispensing optics. Discussion on procedures involved in dispensing spectacles Dispensing optics II (practical work in the optometric clinic / Didactic lecture) UNIVERSITY OF CAPE COAST  PRACTICAL ROTATIONS Design schedules Outline Observing various procedures in dispensing clinic Knowing various tools in the workshop Use of the various tools in the workshop Lens meter Glazing machine Different types of pliers for repair and adjustment Frame selection UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRIPTION INTEPRETATION Medical Prescription: A prescription, often abbreviated ℞ or Rx, is a formal communication from a physician or other registered health-care professional to a pharmacist, authorizing them to dispense a specific prescription drug for a specific patient. UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION SPECTACLE PRESCRIPTION : Often abbreviated Rx or SRx, is a formal communication from an eyecare physician to an optician, authorizing them to dispense a specific ophthalmic lens for a specific patient. UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION TECHNICAL DEFINITION FOR SPECTACLE PRESCRIPTION Information about a spectacle or ophthalmic lens (refractive power, and other specifications (ref index, protective feature photo) Written and signed by a eyecare professional from an accredited or recognized eyecare center On a specially designed form/sheet for dispensing to a patient/client UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION CONTENT OF A VALID / STANDARD SPECTACLE PRESCRIPTION FORM Name of practice and address (clinic, hospital, optometric center, optical center). Type of prescription form i.e. Spectacle prescription form (guides patient). Demographic Data (Why?) o Name o Age o Gender o Address o Occupation Date of Prescription/ Expiration date UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION Lens information o Power of the lens indicated for both eyes ▪ Axis indications if cylindrical lenses ▪ Add indications if bifocal lenses or multifocal lenses o Type of lens prescribed ▪ Single vision lenses ▪ Bifocal lenses ▪ Progressive lenses ▪ Contact lenses UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION Lens information o Specifications of the lens prescribed ▪ Materials Plastic Glass ▪ Protective features Photochromic Tint Plane white Antireflective lens Anti-abrasive lenses ▪ Refractive index of lens indicated 1.49 1.56 1.60 etc UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION Fitting requirement o Pupillary distance o Segment height o Fitting height o Vertex distance etc. Reason for the spectacle o Far vision o Reading or near vision only o Both reading and near vision ( all time wear) o Protection o Night driving etc. UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION Other necessary information if any (not mandatory) o Education o Next review date Signature of Prescriber o Very important o Cannot dispense if prescription is not signed UNIVERSITY OF CAPE COAST SPECTACLE PRECRIPTION INTEPRETATION UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION INTEPRETATION OF SPECTACLE PRESCRIPTION This is the first step in the spectacle dispensing process. Professional need to understand the prescription given before he can dispense it properly All information thus need to be synthesize my the dispenser with no ambiguities UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION Step one: Ensure all mandatory portions of the form are indicated and filled by the prescriber. Dispenser has no right to add or eliminate any indications without approval or permission from the prescriber. To achieve this, interpretation begins from the top of the prescription (clinic information and patient’s demographic data) to the base (doctor’s signature and stamp). Why? To ensure that the prescription: o is for the patient o is coming from a professional in a recognized and accredited health facility UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION Step two: Synthesizing or understanding the lens information. This includes understanding: The power of lens given (ensuring that all relevant spaces are filled and others are cancelled out) The type of lens with all relevant specifications indicated Note: Dispensers knowledge in ophthalmic lenses (especially transpositions) is very vital here UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION Step three: understanding the purpose of wear of lens prescribed. Is it for all time wear, reading only, far vision only, for protection only etc. Step four: Link the information so far to the demographic data of patient (especially age). Step five: Reconcile all information so far to make meaning. Ask for clarification from the prescriber if: 1. any missing information 2. or there is ambiguity UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION Step six: An expect dispenser should have the correct diagnosis (or good impression) of patient’s condition at this stage. Prescriber is not mandated to inform dispenser of the diagnosis by indicating it on the prescription form. Step seven: Lastly be able to summarize a prescription as follows: “ Before me is a patient ( e.g. 3 year old Kofi Agyeman) diagnosed with a condition (myopia/ hyperopia/ astigmatism) by Dr. Darko-Takyi (name of doctor) of the Optometric clinic (name of clinic), and requires Single Vision /Bifocal/ progressive lens (lens type) with specifications (Photochromic, tinted, Antireflective etc) for all time wear, reading only, protection, computer use etc (the reasons for wear). UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION SAMPLE CASES FOR PRACTICE Interpret the following spectacle prescriptions using the following guidelines Possible diagnosis Possible age of patient with justification Possible lens type Other applicable specifications Necessary fitting considerations Indicate specific demand prescriptions Indicate if prescription is wrong Summarize the prescription Where applicable, indicate the powers for reading only, far vision only, both reading and far vision. Indicate the equivalent spherical prescriptions for both eyes where applicable. UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION Possible diagnosis Possible age of patient with Sphere Cylinder Axis VA @ prisms ADD VA @ Near justification Possible lens type distance Other applicable OD -0.50 90 6/5 - - - specifications Necessary fitting considerations OS -1.00 180 6/5 - - - Indicate specific demand prescriptions Indicate if prescription is wrong Summarize the prescription Where applicable, indicate the powers for reading only, Sphere Cylinder Axis VA @ prisms ADD VA @ Near far vision only, both reading distance and far vision. Indicate the equivalent spherical prescriptions for OD -2.00 -0.75 90 6/5 - - - both eyes where applicable. OS -5.00 -1.25 6/5 - - - UNIVERSITY OF CAPE COAST  SPECTACLE PRESCRITION INTEPRETATION Possible diagnosis Possible age of patient with Sphere Cylinder Axis VA @ prisms ADD VA @ justification distance Near Possible lens type Other applicable specifications OD +0.25 - - 6/5 - - - Necessary fitting considerations OS +0.75 - 0.50 - 6/5 - - - Indicate specific demand prescriptions Indicate if prescription is wrong Summarize the prescription Where applicable, indicate the powers Sphere Cylinder Axis VA @ prisms ADD VA @ for reading only, far vision only, both distance Near reading and far vision. OD - - - 6/5 - +2.00 N.5. Indicate the equivalent spherical OS - - - 6/5 - +2.00 N.5. prescriptions for both eyes where applicable. UNIVERSITY OF CAPE COAST  SPECTACLE PRECRIPTION INTEPRETATION Possible diagnosis Sphere Cylinder Axis VA @ prisms ADD VA @ Possible age of patient with distance Near justification Possible lens type Other applicable specifications OD -2.00 - - 6/5 - +3.00 N.5 Necessary fitting considerations OS - 0.75 - - 6/5 - +3.00 N.5 Indicate specific demand prescriptions Indicate if prescription is wrong Summarize the prescription Where applicable, indicate the Sphere Cylinder Axis VA @ prisms ADD VA @ powers for reading only, far distance Near vision only, both reading and far vision. OD +0.25 +1.00 005 6/5 - +1.75 N.5 Indicate the equivalent spherical prescriptions for both eyes OS +0.75 -1.25 180 6/5 - +1.75 N.5 where applicable. UNIVERSITY OF CAPE COAST  SPECTACLE PRECRIPTION INTEPRETATION EQUIVALENT SPHERES To convert an astigmatic prescription into its spherical equivalent forms, divide the cylinder component by two and add to the spherical component. Example, +1.00 DS /- 1.00 DC x 90 will be + 0.50 DS Reason why dispensers and prescribers may want to give spherical equivalents Client cannot cope with cylinders If cylinder component is too small and insignificant If client urgently needs the spectacles at that point in time. Do not give spherical equivalent if: Cylinder is too large and significant Patient cannot cope with spheres NOTE: Always confirm from clients, the clarity and comfort before dispensing UNIVERSITY OF CAPE COAST  SPECTACLE PRECRIPTION INTEPRETATION NOTE THE FOLOWING BEFORE MOVING TO FRAME SELECTION AND FACE MEASUREMENTS Always inquire from the prescriber if the prescription in not clear to you Always prompt the prescriber if there in no signature Do not make any alterations or modifications to the spectacle prescription without permission from the prescriber. Ensure that you have completely understood the prescription before moving on to frame selection and measurement of fitting requirements. A good understanding and interpretation will guide dispenser to o Select the right frame and lens to fit for patient o Understand which required face and frame measurements to measure for accurate fitting o Give proper advice to patient after fitting. UNIVERSITY OF CAPE COAST  ORDERING LENSES Outline of topic Define/ Describe ordering Describe content of an ordering form Describe and differentiate the different types or medium of orders What happens to wrong orders and overdue orders Who bears the cost of wrong orders UNIVERSITY OF CAPE COAST  ORDERING LENSES Define Ordering lenses: the process a clinic goes through to buy a spectacle prescription from a surfacing laboratory. Optician or a specially trained person in the clinic or optometric center is designated to do this on behalf of the clinic. Special order forms are used in ordering to guide two parties. Is advisable that the manufacturers or suppliers own ordering form is used. Reasons: o to limit or eliminate errors or omissions in processing o it directs the one ordering of the specific information the supplier needs on each lens order UNIVERSITY OF CAPE COAST  ORDERING LENSES Content of ordering form Refer to Canada optical ordering form as guide to explain How different is a lens order form from a patients prescription form o Patient prescription form is written and signed by the doctor whilst lens order form is filled by the optician or any trained personnel on behalf of the clinic. o Contains less demographic information; only one being the clinic reference and patients reference. Spectacle prescription form contains more demographic information o Visual acuity is not mandatory and indicated on the lens order form o Bulk of the information is the lens prescription and its specifications o Patients prescription form is the property of the patient, Lens order form is a property of the clinic and will be used by supplier UNIVERSITY OF CAPE COAST ORDERING LENSES UNIVERSITY OF CAPE COAST  ORDERING LENSES How to fill the lens order form Use separate form for each job order. Reason: the form travels with the material and each processing Specify the instruction on the form i.e. if lens only or frame attached for fixing and others Do not include any other information on the form that is not applicable to the SRx In writing prescriptions Indicate right eye first before left eye Write powers in specific cells ie. Sphere cell, cylinder cell, axis cell, prism cell, ADD cell etc. Write powers in two decimal places State the axis but do not put a degree sign after the number representing the desired meridian. Reason: it may be read for an extra zero Specify the notations used in deriving the prescription Give other specific relevant information in portion for additional information e.g. specifying segment height or type of segment top for bifocal or type of progressive lens or corridor length for progressive lenses. UNIVERSITY OF CAPE COAST  ORDERING LENSES Methods of ordering Sending the order form. o Posting o Vehicle o Courier systems o Personal delivery Telephone calls o Specifically read all the relevant aspects to the supplier o Reader must be clear Electronic transfer / mails o Emails o Fax machines o Watsup line QUESTION: Discuss the advantages and disadvantages of these different methods over each other. UNIVERSITY OF CAPE COAST  ORDERING LENSES What happens to wrong delivery of orders? Depends on the supplier and clinics arrangements Who made the error bears the cost Sending wrong orders back to supplier UNIVERSITY OF CAPE COAST  ORDERING LENSES Danger with ordering lenses only without specifying frame size and dimensions The lens can easily be too large or too small. Too large, waste of material and money; too small will require manufacturing different one, thus cost implications and delay in delivery. This can only be detected during fitting time. Solution to this: Trace the shape of the eye wire of the front using a: Remote frame shape tracer connected to a computer which can be sent electronically Manual frame shape tracer (cut the pattern) and send together with order to guide manufacturer C-size or circumference of the lens using a circumference guage. When the circumference is known, the lens size can be reproduced. Can use some parameters of the boxed lens such as: o Lens size or eyesize o Effective diameter o Vertical boxing length Note: Ideally lens diameters are measured to suit almost all ophthalmic frames; if your patient’s frame looks bigger than the expected diameter, guide the manufacturers. UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOPS Also called Edging Optical Workshop or Glazing Workshop Usually found in hospitals, clinics or optical centres. Different from Surfacing Laboratory like Canada Opticals Is a workshop for: fitting lenses into spectacle frame to make a pair of spectacles Repair of spectacles Adjustment of spectacles Surface treatement or tinting of plastics UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Glazing or Edging is the act of cutting prescription lenses and reducing them to shapes that can be fitted into spectacle frames to form a spectacle Main instrument is the Edger or Glazing Machine Most financial rewarding UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Neigbours In order to be efficient, edging workshop must work in close co-operation with A well managed stockroom Uncut lenses Frames Dispensing room (show room) Displays frames and its accessories UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP REQUIREMENT FOR OPTICAL WORKSHOP Optical bench Stools Job trays Drying cloths Overall / Coat Electricity requirements Ventilation Instruments and equipment UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Optical bench Height appropriate for standing or sitting Has enough space to work Narrow enough to pass through the doorway Drawers to keep completed works or works yet to be done No crowded surface Ideally, surface should be formica plastic laminated UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Stools Can be made of any locally available material; metal or wood Correct height for the worker Modification for a disabled Foot rungs for long term comfort UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Job trays To keep jobs yet to be done Has three areas- 2 top smaller areas for keeping the lenses for right and left eye 1 large area below to keep patients prescription and frame Can be made of wood orplastic UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Drying Cloths Linen drying cloths needed To dry the lenses during the edging process Ideally 10 required Two for each working day- one to lay on workers lap when edging and one to clean the lenses after edging Suitable size is 70 cm * 40 cm UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Overall or coat Ideal is white coat To protect body from white glass or plastic powder UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Cleaning equipment Strong stainless steel or concrete wash basin with running water To keep workshop and machine clean UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Electricity Adequate single phase electrical outlets On bench, at least four outlets are required for which adapters can be ultilized Use three pin earthed electrical plugs Water is employed in the edging process so all machines must be properly earthed UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Ventilation Good one required Open windows to replace stale unwanted air It should be possible to lock and secure the workshop UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Machines Edger or Glazing machine Plastic Frame heater Focimeters Drilling machines Grooving machines Polishing machines Centration machines Burner for tintings UV testers UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Others Screw driver sets Plier sets Scissors Others find out NOTE Discuss Edger Focimeter use UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Setting up Optical work bench Defines how the optical workbench is layed out for work Note the following when laying out How work flow in the workshop Ideal is to lay equipment from left to right?? Space out items for easy location Safety Do not set electrical cables closer to water UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Glazing Machine Types Manual edger Automatic edger Maintenance UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Automatic Edger Automatically cuts the lens after been set by the optician Uses a pattern cutter and cuts lens according to the pattern set Uses diamond wheels to cut the lens Plug to an electric source Continuous water flow to cool the lens UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Manual Edger / Hand Edger Optician manually holds the len and cuts it into the desired pattern No pattern cutter required Fitted with good quality diamond wheel Not less than 150mm (6 inches) diameter and 25mm (1 inche) wide Plug to an electric source Has a motor attached to the diamond wheels to produce energy to run the wheels UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Forms of diamond wheel Rough ones Smooth ones Grooved ones for bevelling UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Models of Hand Edger Closed Circuit hand edgers Open Circuit hand edgers Closed Circuits Has a bath of water into which a piece of sponge rubber is set so that it deposits a fine film of water onto the rotating diamond wheel Waste glass accumulates in the bath and sponge and must be thoroughly cleaned out daily. UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Open Circuits Edger is connected to a constant water supply and drainage system Water from a tap is fed into the top of the spray guard via plastic pipe Tap adjusted so water drops on diamond wheel at one drop a seconds As the diamond spins, a piece of sponge rubber wipes the water to a fine film onto the wheel Waste glass and water drains out of the machine via a drain at the bottom Some machines have settlement tanks. Water and glass dust drain down ina steeply inclined pipe to a settlement tank UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Maintenance of Hand Edger Should be carried out only after disconnecting the machine from electric supply Cleaning is needed on a daily basis to ensure no build up of glass dust Sponge in the water bath should be removed and rinsed out every day, then replaced Need for dressing the diamond wheel as wheel can become slow at edging Dressing is the act of sharpening a diamond wheel Dressing stick (carborundum stone) is used UNIVERSITY OF CAPE COAST  OPTICAL WORKSHOP Maintenance Waste products of optical workshop are glass and plastic dust or powder Glass chips Chipping UNIVERSITY OF CAPE COAST  MANAGING STOCK LENSES Arranged from smallest power to highest power According to the sign whether plus or minus Power range must be labelled on the box or shelf Need to tally all powers for restocking Number of lenses depends on capital Stock more moving lenses and less high ones UNIVERSITY OF CAPE COAST PROCEDURE FOR GLAZING IN WORKSHOP Sorting lens Marking lens Creating the pattern on lens Climping Rough glazing Smooth glazing Beveling Fitting into frame Final adjustment UNIVERSITY OF CAPE COAST  FOCIMETER USE Parts and their uses recape Set-up of focimeter Checking spherical lenses Checking cylindrical lenses Take advantage of rotations to practice this. Will test this in Second Quiz in first week of MAY UNIVERSITY OF CAPE COAST  FITTING LENSES FIELD STUDY Fitting single vision lenses Fitting bifocal lenses Fitting progressive lenses Need to show evidence in learning above Emphasize on marking reference points like optical centers, cylindrical axis, fitting points, pattern marking. Submit first six weeks work for assessment by Friday. UNIVERSITY OF CAPE COAST  NOTE Read Chapters 7,8,9 and 10 Reference point placement, Fitting single vision lenses Fitting bifocal lenses, Multifocal height, and Blank size determination. Fitting progressive lenses UNIVERSITY OF CAPE COAST PRISMATIC LENSES UNIVERSITY OF CAPE COAST PRISMATIC LENSES UNIVERSITY OF CAPE COAST UNIVERSITY OF CAPE COAST  SPECTACLE FRAME MATERIALS Epoxy resin known under the trade name of Optyl. Thermosetting material: percieved as difficult to work with as cannot easily adjust thermoelastic. This means that it will bend when heated and will return to its original shape when reheated. Out of fashion now approximately 30% lighter than cellulose acetate. Hypoallergenic: appropriate for those who might be allergic to other types of frame materials. UNIVERSITY OF CAPE COAST  SPECTACLE FRAME MATERIALS Nylon and Nylon-Based Materials Thermoplastic Nylon is a material of high flexibility. When used alone in spectacle frames, nylon will lose that flexibility unless periodically soaked in water overnight. Otherwise, over time, it will become brittle. “Pure” nylon was previously used extensively for sports eyewear. It has also been used for over-the-counter sunglasses. It is now being combined with other material for added strength and stability, remaining a part of the array of frame materials in use. UNIVERSITY OF CAPE COAST  SPECTACLE FRAME MATERIALS Carbon Fiber Carbon fiber material is used to create a thin, strong frame. This material is made from strands of carbon fibers combined with nylon. It is not adjustable and is consequently used mainly for frame fronts. The temples are generally made from another material. In other words, if a carbon fiber frame does not fit well in frame selection, do not plan on making it fit well later on. The principle advantage is the light weight that can be achieved. Carbon fiber is 60% the weight of cellulose acetate. Not only is the material light weight, but because of its strength, it can also be made thinner. Since carbon is black, frame colors will be opaque and are limited. Some problems may be encountered with breakage in cold weather. Because of the thermal problems, it is imperative that the material not be directly worked with right after it has been outside. (For more information on working with carbon fiber material UNIVERSITY OF CAPE COAST  SPECTACLE FRAME MATERIALS Polycarbonate Polycarbonate is a material usually associated with lenses, but can be molded into frames. Frames made from polycarbonate are primarily for sport or safety purposes. When made for nonprescription purposes, the lenses and frame are molded as one unit. Frames (and lenses) made from polycarbonate are very impact resistant. Unfortunately, polycarbonate frames do not work well for conventional eyeglasses because of their resistance to adjustment. They are better suited for the type of sports glasses that are held in place with elastic straps (Figure 1-22) or for shield types of glasses that may be used either alone or worn over conventional glasses (Figure 1-23). UNIVERSITY OF CAPE COAST  SPECTACLE FRAME MATERIALS Kevlar Kevlar is a material that is also mixed with nylon. Is a strong, lightweight ophthalmic frame material. Kevlar will remain stable over a large temperature range, but is difficult to adjust. Although it becomes pliable with heat, it will not shrink or stretch. UNIVERSITY OF CAPE COAST  SPECTACLE FRAME MATERIALS Rubber Some sports eyewear and sunglass frames may be made from a combination of nylon and rubber. As would be expected, these frames are flexible and will return to their original shape, but are not adjustable. UNIVERSITY OF CAPE COAST  SPECTACLE FRAME MATERIALS Combinations of Plastic Materials There are numerous possible combinations of plastic materials. These include materials sometimes called memory plastics. Memory plastics are tough and flexible. They can be bent or twisted and still return to their original shape. Not all composite plastic materials are memory plastics. Other composite plastics combine various materials to produce frames and frame parts for specific needs and purposes. UNIVERSITY OF CAPE COAST  MATERIALS FOR SPECTACLE FRAMES https://www.opticianonline.net/cet- archive/4377 Materials for spectacle frames UNIVERSITY OF CAPE COAST  MATERIALS FOR SPECTACLE FRAMES Metal spectacle frame materials include: Gold frames Silver Stainless steel Aluminium Nickel Titanium Bronze Magnesium Combination of metals UNIVERSITY OF CAPE COAST  MATERIALS FOR SPECTACLE FRAMES Gold Frames Used in alloy form Described depending on the amount of gold found in the frame Amount of gold specified e.g 18k gold frame. Usually not less than 1/10 12kerat gold. Colour of frame depends on what type of metal is used with gold to make the gold alloy. UNIVERSITY OF CAPE COAST  MATERIALS FOR SPECTACLE FRAMES Gold Frames Same system used to classify gold parts is used in describing gold spectacle frames Fine gold: Has no metal in it, chemically pure gold i.e. 24 kerat fine gold. Ie all 24 parts of the material is gold. Solid gold: mixture of gold and other metal e.g. 12 kerat means 12 parts of the total 24 parts are gold Gold filled: made of other metal and coated with gold alloy One twentieth of the articles total weight must be gold ie. 1/10 of 12k Gold Plated: made of other metal and surface plated with gold by an electrolyte process UNIVERSITY OF CAPE COAST  MATERIALS FOR SPECTACLE FRAMES Silver Not very serviceable as a spectacle frame Due to its softness Being replaced by white gold UNIVERSITY OF CAPE COAST  MATERIALS FOR SPECTACLE FRAMES Stainless steel Corrosion resistant steel containing chromium Chromium is hard bluish white metallic element which increases hardness and corrosion resistance Makes a good and durable spectacle frame Noncorrosive Hypoallergenic UNIVERSITY OF CAPE COAST  MATERIALS FOR SPECTACLE FRAMES Aluminum Makes a good frame Its light weigh Resistant to wear and rusting It has the ability to be anodized, making color variations possible Anodized- coat metal with oxides to give colour UNIVERSITY OF CAPE COAST  MATERIALS FOR SPECTACLE FRAMES Nickel Formally used in place of Gold Not used frequently now Not attractive compared to other metals UNIVERSITY OF CAPE COAST  MATERIALS FOR SPECTACLE FRAMES Titanium Silvery metallic chemical element- a strong, light weight, corrosion resistant silvery metallic element Very durable Noncorrosive Light weight and flexible Hypoallergenic Very expensive Part of the alloy for aerospace industry UNIVERSITY OF CAPE COAST  MATERIALS FOR SPECTACLE FRAMES Combination materials e.g nickel- titanium frames, bronze-silver frames Read about Bronze UNIVERSITY OF CAPE COAST  MATERIALS FOR SPECTACLE FRAMES Magnesium frames Aluminum magnesium frames (combination) UNIVERSITY OF CAPE COAST  MATERIALS FOR SPECTACLE FRAMES READ ABOUT WOODEN MATERIALS FOR SPECTACLE FRAMES UNIVERSITY OF CAPE COAST  SYSTEMS OF FRAME MEASUREMENTS The purpose: To give complete understanding of frame dimensional properties. To give knowledge to develop skill in frame selection. Two Systems of Spectacle frame Measurement Datum system Boxing system UNIVERSITY OF CAPE COAST  SYSTEMS OF FRAME MEASUREMENTS DATUM SYSTEM Previously used system for measuring lenses, the datum system preceded the currently used boxing system. Was established as a system of reference points for frames and lenses This made that placement of lens optical centers and bifocal segment heights consistent and easy. The lens was placed as it should sit in the frame. Horizontal lines were drawn at the highest and lowest edges of the lens. A line drawn halfway between the two horizontal lines and parallel to them was known as the datum line. The width of the lens along the datum line was called the datum length or eye size. The point along the datum line halfway between the edges of the lens is the datum center. The depth of the lens, measured as the vertical depth through the datum center, was the mid-datum depth. mid datum depth may not always be equal to the distance between the horizontal tangents. It usually depends on the shape of the lens. UNIVERSITY OF CAPE COAST  SYSTEMS OF FRAME MEASUREMENTS BOXING SYSTEM Improved on the foundation provided by the datum system. Kept the two horizontal lines against the top and bottom in the datum system and added two vertical lines. These vertical lines are placed against right and left edges of the lens. All four lines form a box around the lens UNIVERSITY OF CAPE COAST SYSTEMS OF FRAME MEASUREMENTS UNIVERSITY OF CAPE COAST  SYSTEMS OF FRAME MEASUREMENTS Horizontal Midline (180-degree line) This is a horizontal line halfway between the top and bottom of the lens. Sometimes referred to as the datum line as in the datum system. More commonly referred to in the boxing system as the horizontal midline or the 180-degree line. UNIVERSITY OF CAPE COAST  SYSTEMS OF FRAME MEASUREMENTS Geometric Center The center of the lens Is the point on the horizontal midline halfway between the two lens-bordering vertical lines. Also called the boxing center of the edged lens. This term does not imply anything about the optical positioning of the lens. UNIVERSITY OF CAPE COAST  SYSTEMS OF FRAME MEASUREMENT Size The size of the lens is the length and depth of the box containing the lens. The horizontal length is now commonly referred to as the eye size when referring to the frame and the lens size (lenses). Both are measured in millimeters. Most practitioners normally refer to this horizontal measure “A” as the lens size. The letter “B” denotes the vertical measure of the box enclosing the lens. Both “A” and “B” are in a sense independent of lens shape. The letter “C” refers to the width of the lens itself along the horizontal midline.1 This can vary considerably from the A dimension. The C dimension of a lens (seldom used) was the eye size in the datum system. The C dimension of a lens should not be confused with the “C- size” of a lens. C-size is the circumference of the edged lens. UNIVERSITY OF CAPE COAST  SYSTEMS OF FRAME MEASUREMENT Horizontal boxing dimensions of frame begins at the inside of the groove on one side and extends across the lens opening to the farthest part of the groove on the other. We cannot see the inside of the groove when looking from the front. This means we can estimate where it will be and hold the ruler so that the zero point is at the position of the left-hand side of the groove. Then we need to read the ruler at the position where the groove will be on the right. If the opening itself is measured, then about ½ mm per side needs to be added to the measure to allow for the depth of the groove. This may vary somewhat, depending upon the depth of the groove. UNIVERSITY OF CAPE COAST  SYSTEMS OF FRAME MEASUREMENT Effective Diameter The effective diameter of a lens is found by doubling the distance from the geometric center of the lens to the apex of the lens bevel (slanting edge ) farthest from it. This measurement helps determine the smallest lens blank from which the lens can be cut. (Chapter 5: Determining Lens Blank Size.) UNIVERSITY OF CAPE COAST  SYSTEMS OF FRAME MEASUREMENT Frame Difference The difference between the horizontal and the vertical measurements. Is measured in millimeters. The larger the difference, the more rectangular the enclosing box appears. Frame difference is sometimes referred to as lens difference. UNIVERSITY OF CAPE COAST  SYSTEMS OF FRAME MEASUREMENT Distance Between Lenses (DBL) or Bridge Size Distance between the two boxes when both lenses are boxed off in the frame. Note: This is usually synonymous with bridge size, although it is important to note that manufacturers not adhering to the boxing system may mark a bridge size that does not correspond to the distance between lenses. Bridge size or DBL is measured on the frame as the distance from the inside nasal eye wire grooves across the bridge area at the narrowest point (Figure 2-5). This distance is measured in millimeters. Naturally, two frames having the same DBL will not necessarily fit the same person in the same manner because of variations in lens shapes. UNIVERSITY OF CAPE COAST SYSTEMS OF FRAME MEASUREMENT UNIVERSITY OF CAPE COAST  SYSTEMS OF FRAME MEASUREMENT Geometric Center Distance (GCD) The distance between the two geometric centers of the lenses. It can be measured more easily as the distance from the far left side of one lens opening to the far left side of the other (i.e., from the left side of one “box” to the left side of the other “box.”) Or the geometric center distance can be calculated by simply adding the eye size to the DBL. The GCD is also known by three other names: Distance between centers (DBC) Frame center distance Frame PD The term frame PD is commonly used in dispensing, but has no relationship to the wearer’s interpupillary distance or distance between pupil centers.* UNIVERSITY OF CAPE COAST  RULERS FOR MEASURING SPECTACLE FRAMES AND FACE Reading assignment. Will test them on this. UNIVERSITY OF CAPE COAST  MEASURING SPECTACLE FRAME TEMPLES Temple lengths are expressed in millimeters. Temple length may be measured in one of the following ways. Overall Temple Length Length to Bend (LTB) Length to drop Front to Bend (FTB) UNIVERSITY OF CAPE COAST  MEASURING SPECTACLE FRAME TEMPLES Overall Temple Length The overall temple length is the distance from the center of the center barrel screw hole to the posterior end of the temple, measured along the center of the temple (Figure 2-6, A). Many times the center of the barrel screw hole will match the position of the butt end of the temple. But this is not always the case. Also, when measuring the overall temple length, it is necessary to measure around the bend and not in a straight line, unless of course the temple is straight. The easiest way to do this is shown in Figure 2-7, A through D. Comfort cable temples are measured in terms of overall length. The actual measurement is done by grasping the tip and extending the temple along the ruler (Figure 2-8). UNIVERSITY OF CAPE COAST  MEASURING SPECTACLE FRAME TEMPLES Length to Bend (LTB)/ length to drop An older method of measuring temple length is in terms of the length to bend (LTB). This is measured from the center of the barrel to the middle of the bend. The distance from the middle of the temple bend to the end of the temple is known as the length of drop UNIVERSITY OF CAPE COAST  MEASURING SPECTACLE FRAME TEMPLES Front to Bend (FTB) If the endpieces wrap around in a swept- back manner, there is a distance between the plane of the frame front and the actual beginning of the temple. In this case, the temple length could be specified as frame to bend (FTB) which would be slightly longer than LTB. This measurement method is seldom used. UNIVERSITY OF CAPE COAST  FRAME SIZE INSCRIPTIONS Most frames are marked according to size with three measurements: Eye size, DBL, and temple length. Metal frames that are manufactured from “rolled gold” are also marked as to the amount of gold found in the frame. UNIVERSITY OF CAPE COAST  FRAME SIZE INSCRIPTIONS When a frame marking such as 50_20 is seen, it means that the eye size is 50 mm and the distance between lenses is 20 mm. The box between the numbers means that the eye size is measured according to the boxing method 50 □ 20 - 135; it also serves to separate the two numbers and prevent confusion. The eye size and DBL are sometimes simply marked 50-20 or 50/20. UNIVERSITY OF CAPE COAST  FRAME SIZE INSCRIPTIONS Location of Markings On a plastic frame the marking may be found in any of several places. inside of the nosepad, Upper outer section of the eyewire. back side of the endpiece (the temple must be folded closed to find it). Sometimes the eye size is printed on one endpiece and the DBL on the other. temple length is printed on the inner side of the temples. Some manufacturers put all three measurements on the temple. Unfortunately this leads to confusion when temples are exchanged. UNIVERSITY OF CAPE COAST  FRAME SIZE INSCRIPTIONS Location of Markings On metal frames and frames with metal chassis, the eye size and DBL are usually on the: inside of the bridge, although occasionally they are printed on the underside of a top reinforcing bar, or again, on the temples. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Common Ones include Pupillary distance, PD Segment height (bifocals) Fitting height (progressive lenses) UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Pupillary Distance (PD) The anatomic PD is the distance from the center of one pupil to the center of the other pupil, measured in millimeters. Purpose To align the visual axis of patient with optical center of lens (in frame) to prevent unwanted prismatic effects during distance or near fixation. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Consequence of not taking PD or taking wrong PD Failure to accurately determine the interpupillary distance results in a misplacement of the optical center of the lenses. This induces unwanted prismatic effects, requiring the wearer to turn his eyes inward or even outward, to keep from experiencing double vision. Over time, this effort causes visual discomfort and can result in a decreased ability of the eyes to work together in binocular vision. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING When to take and apply PD measurement Before ordering and fitting prescription spectacles Spectacle frame selection Decentration Before doing a visual examination refraction binocular vision assessment(phoropter) UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Instrument to take PD Simple millimeter rule PD rule PD measuring instrument (Digital Pupillometer) Automated instruments like auto-refractive Technique for measuring PD distance near depending on type of prescription lens (in dispensing spectacles) and type of examination (in visual examination) UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Technique Can be either binocular PD or monocular PD Mostly depends on face shape. Symmetrical faces may require binocular PD Asymmetrical faces require taking monocular PD UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING TECHNIQUE FOR BINOCULAR DISTANCE PD MEASUREMENT 1. Dispenser positions at 40 cm (16 in). 2. Dispenser closes right eye, subject fixates on dispenser’s left eye. 3. Dispenser lines up zero point on subject’s right eye at the pupil center, left pupillary border, or left limbus. 4. Dispenser closes left eye, opens right eye; subject fixates right eye. 5. Dispenser reads off scale directly in line with left pupil center, left pupillary border, or left limbus. 6. Dispenser closes right eye, opens left; subject fixates left eye. 7. Dispenser checks to make sure zero point is still correct. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Common Causes of Errors parallactic error- If the measurer’s PD differs significantly from the subject’s; lines of sight will not be parallel. if the PD rule is not tilted on the subject’s nose so that the scale is in the most recessed area. The most recessed area corresponds to the approximate position where the spectacles will be worn. if the dispenser is too close to the subject i.e. less than the normal 40 cm (16 inch) distance. if the subject is strabismic. If the subject’s head moves. Dispenser moves his or her head. if the person measuring does not occlude one eye at a time to ensure sighting from directly in front of the subject’s eye under observation. If subject does not look directly at the measurer’s pupil during the test. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Common Difficulties and Their Solutions Difficulty in determining exact centre of pupil The edge of the pupil may be used as a measuring point if both pupils are the same size. Measurement is read from the left side of one pupil (temporal side) to the left side (nasal side) of the other. Measuring from the inside edge (nasal edge) of one pupil to the inside edge (nasal edge) of the other would give an artificially low reading From the outside edge (temporal edge) of one pupil to the outside edge (temporal edge) of the other, an artificially high reading. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING When a person has dark irises or unequally sized pupils When the subject has dark irises, the outside edge of the limbus may be used as the zero reference point and the inside limbal edge of the other eye as the measuring point It may be difficult to use either the center or the edge of the pupil. In this case, the dispenser may use the limbus edge— the sharp demarcation between white sclera and dark iris. Because the pupil is displaced 0.3 mm nasal ward from the center of the limbal ring, a limbal measure will be approximately 0.5 mm greater than the measure found using pupil centers.) Take difference out. the same sides of the limbus (both left and both right) must be used, or an extremely large error is induced. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Dispenser Cannot Close One Eye. This can be remedied by occluding (covering) the eye with the free hand. The practice of holding the lid down with one finger gives an unprofessional appearance, especially when wearing glasses. Occluding the eye with the hand held flat appears to be a natural part of the test and does not reveal a person’s inability to close only one eye. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Dispenser Visually Impaired in One Eye. If the dispenser is blind in one eye, or has visual acuity too poor to allow the ruler to be read accurately, then the technique is modified. The dispenser places the good eye directly in front of the subject’s right eye and at the normal distance. The zero mark is lined up as usual. The dispenser then moves sideways until the good eye is positioned in front of the subject’s left eye and the measurement is read. Unfortunately this method can easily lead to parallax errors. The most desirable solution for someone with this difficulty is to use another type of instrument that only requires the use of one eye. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Subject Is Strabismic. the PD rule method of measurement may then give an artificially high or low reading. To determine a true reading, simply cover the subject’s eye not being observed. This ensures that the subject is fixating with the eye under observation and ensures that it is not turned unless eccentric fixation is present. Even if eccentric fixation is present, the PD measurement is still correct, since the subject never uses this eye in any other position relative to the dominant eye. In instances of constant deviation, the wearer is better served if the lenses are centered in front of the pupils, even for the eye that is turned. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Subject Is an Uncooperative Child. the dispenser may have to take a canthus- to-canthus measurement. The canthus is the corner of the eye where the upper and lower lids meet. This is done by measuring from the outer canthus of one eye to the inner canthus of the other eye. Unfortunately, Figure this measurement is not entirely exact, since the inner canthi of the eyes encroach farther across the sclera with younger children. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING MONOCULAR DISTANCE PD This refers to PD specified for each eye independently To determine accurately, PD of asymmetrical faces. Since faces are not always symmetrical, it is often necessary to specify the PD for each eye independently. The main goal in taking the PD is to eventually place the optical centers of the lenses directly in front of the subject’s eyes to prevent any undesired prismatic effect. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING The procedure consists of the following three steps: 1. Measure the binocular PD as described earlier in the chapter. Use the center of the pupil as the reference point. 2. Before moving the ruler, note the scale reading on the ruler at the center of the nose. This is the right monocular PD. 3. Subtract this reading from the binocular reading to obtain the left monocular PD. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Procedure for Measuring Monocular PDs Using the Frame UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING NEAR PD The near PD is required for single vision reading glasses or for multifocals. For single vision reading glasses, the lenses are set so that their optical centers will be in the lines of sight of the eyes when the eyes are converged for reading. For multifocals, the distance portion is ground to correspond to the distance PD, while the bifocal or trifocal portion is decentered inward to be properly situated for near vision. The near PD can be either measured or calculated. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Steps in Measuring the Near PD 1. Dispenser places his or her dominant eye in front of subject’s nose at the subject’s near working distance. This is the distance for which the near prescription is intended—normally 40 cm (16 in). 2. Dispenser closes the non-dominant eye. 3. Subject fixates dispenser’s open eye. 4. Dispenser places zero point of PD rule at center of subject’s right pupil. 5. Dispenser reads scale marking at center of subject’s left pupil. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Recording is Distance / near e.g. PD= 70/66 Watch Video on how pupillometer is used. Watch video on how other automated pupillometers are used. Gauges the corneal reflexes UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Pupillometer use a corneal-reflection-style instrument to measure a PD based on pupil center distances. To do this, the hairline within the device is moved to the center of the pupil rather than the center of the corneal reflection. The corneal reflection method is definitely the method of choice when measuring a PD for someone with pupils dilated from a recent eye examination. UNIVERSITY OF CAPE COAST  FACE MEASUREMENT DURING SPECTACLE DISPENSING Photographic Instruments for Measuring PD make use of a photograph of the wearer’s eyes with the frame in place. The frames are adjusted as they are to be worn. The wearer fixates a light in the instrument, and the photo is taken. PD and segment height measurements are determined using the picture. UNIVERSITY OF CAPE COAST  FRAME SELECTION DEFINITION Frame selection refers to guiding a person make best choice of a frame for fitting ophthalmic lenses. Basic knowledge required to select frames include: Basic facial shapes and other cosmetic characteristics. Frame types, materials and styles (Vogue) types and magnitudes of ametropia Fitter or dispenser must have these abilities: Ability to know what the frame will look like with lenses prescribed Ability to know how the frame will look on the face of client Ability to know how it will perform in fulfilling the wearer’s needs. UNIVERSITY OF CAPE COAST  FRAME SELECTION Special considerations to understanding topic Using wearers old frame Cosmetic considerations Fitting considerations UNIVERSITY OF CAPE COAST  FRAME SELECTION Valid reasons for patients wanting to use the old frame and not purchase a new one. cost comfort of the old frames Old frame more cosmetic appealing than new ones Old frame still durable. UNIVERSITY OF CAPE COAST  FRAME SELECTION Factors to Consider before Using the Wearer’s Old Frames* Putting new lenses in an old frame may involve putting additional stress on the frame. Older frames may not withstand that stress very well, particularly older plastic frames that have become brittle with age. It is hard to predict how long an old frame will last. Will it last the life of the new lens prescription? If the old frame needs repairing in the future, will there be parts available? Any back-up in case lost- Usually people keep their old glasses as a backup spare pair in case they lose or break their new pair. UNIVERSITY OF CAPE COAST  FRAME SELECTION Factors to Consider before Using the Wearer’s Old Frames continue: Sometimes old lenses can be tinted and the older pair be transformed into prescription sunglasses. particularly true if the only change in a multifocal prescription is in the near vision portion. there is an advantage to having interchangeability of parts should the new frame break (if similar to old one). Does the lab need the old frames to make the new lenses correctly? If so, can the wearer do without their current glasses while the frames are at the laboratory? Are the old frames out of style or nearly out of style? UNIVERSITY OF CAPE COAST  FRAME SELECTION COSMETIC CONSIDERATIONS - NOTE Beauty is subjective not objective Guidance very vital even though client ultimately has final choice Wearer ultimately has final choice, but should not be allowed free rein in selecting a frame. Both new wearers and habitual ones expects and should receive guidance Frame selection is often a process of trial and error Can be time consuming and is frequently frustrating. An experienced fitter aware of the basics of frame selection can save considerable time and earn the wearer’s gratitude by being able to readily select several frames that are obviously suitable. What is cosmetically correct for a given face must be related to whatever styles are in vogue. At a time when narrow frames are in fashion, a person whose face requires a deep frame will not wear one quite as deep as when larger, deeper frames are in style. The person with a narrow interpupillary distance can wear a wide frame more acceptably when everyone is wearing large frames than when everyone is wearing smaller frames. UNIVERSITY OF CAPE COAST  FRAME SELECTION Basic tips to arrive at an aesthetically pleasing and comfortable frame Face shape and frame shape Skin colour Hair colour Patients best colour/ shape UNIVERSITY OF CAPE COAST  FRAME SELECTION Face shape and frame shape Different face shapes Specific considerations for face shapes during frame selections Considerations affecting frame lines Considerations affecting length of the face Considerations affecting facial balance UNIVERSITY OF CAPE COAST  FRAME SELECTION Different face shapes Oval— Considered to be the ideal type Face is vertically oval Oblong— Thinner and longer than usual, With the sides of the head being more parallel to one another than in the oval type Round— More circular than the oval UNIVERSITY OF CAPE COAST  FRAME SELECTION Square— The sides of the face are more parallel than in the oval, With the face being wider and shorter than usual Triangular— The lower part of the face is wider than the upper part Inverted triangular— The upper part of the face, the temple area, is wider than the lower jaw area Diamond— The central section of the face is wider, With the upper and lower extremities of the face narrowing down considerably Heart face- heart shape face UNIVERSITY OF CAPE COAST FRAME SELECTION UNIVERSITY OF CAPE COAST  FRAME SELECTION Hairstyle can be misleading in identifying face shapes in frame selection. Because a hairstyle can also alter the apparent shape of the face, frames are generally chosen to compliment the face as it appears with the hairstyle being worn at the time of frame selection. A radical change in hairstyle may also radically change the effect that the frame has on the face. UNIVERSITY OF CAPE COAST  FRAME SELECTION To simplify the face shapes to help choose frame width and depth, the shapes can be condensed to five shapes: The oval face is considered normal and can wear almost any frame, so only the general rules apply. The oblong face is simply referred to as long. Both the round and the square face fall into the category of the wide face. The erect or base-down triangular face is a category that does not lend itself to condensation. For fitting purposes, the diamond face is included in the inverted or base- up triangular classification, since these shapes are all fit in basically the same manner. UNIVERSITY OF CAPE COAST  FRAME SELECTION Specific considerations for face shapes during frame selections Considerations affecting frame lines Considerations affecting length of the face Considerations affecting facial balance UNIVERSITY OF CAPE COAST  FRAME SELECTION Considerations affecting frame lines What determines the frame lines – The curve or squareness of the upper and lower rims i.e. the basic shape of the lens. Repeating a facial line through the line of the frame emphasizes the facial line. This can be used to advantage provided the line being repeated is complementary or used to achieve a desired effect. Inadvertently repeating an uncomplimentary line can, by the same principle, have an undesirable effect. UNIVERSITY OF CAPE COAST  FRAME SELECTION Considerations affecting frame lines Frame Lines should emphasize facial lines to compliment the face shape for cosmesis) Frame lines should emphasize facial lines by repetition A good frame selection can be simplified by considering first which facial lines are complimentary to the person Those lines should be emphasized through repetition, usually by the upper and lower eye wires. On the other hand, uncomplimentary lines should not be repeated by the frame line. Bone structure defines the facial lines proper. Few faces meet the artistic ideal in bone structure and conformity. UNIVERSITY OF CAPE COAST  FRAME SELECTION What determines the upper and lower areas of frame lines– general rules for cosmetic emphasis Upper area The upper areas of the frame are determined by the eyebrow line. The upper frame area, or upper rim, should have the same basic shape as the eyebrow itself. Too much deviation from this line creates a disharmonious look to the face, roughly similar to the confused effect of wearing stripes with plaids. Ideally the upper rim should follow the lower edge of the eyebrow, leaving it visible. At its highest possible position, the upper rim bisects the eyebrow. UNIVERSITY OF CAPE COAST  FRAME SELECTION Lower area The lower frame areas are determined by the lines of the cheek and jaw. The lower eye wire area near the nose should follow the nasal contour of the face. Lower rim can add a lift to a face that has begun to sag with age. Using an upsweep on either upper or lower rim of a frame tends to counteract the downward lines of the face. In general, a frame with a downward line, which emphasizes the undesirable characteristic, should be avoided. lower rims can help conceal the bags that many people have under their eyes. Frame with fairly thick lower rim are helpful camouflage to bags and undesirable marks. UNIVERSITY OF CAPE COAST  FRAME SELECTION Frame lines can somewhat alter the mood expression of the face, causing the wearer to have a happier, sadder, more stern, or even a somewhat surprised look, depending on the interaction of the frame lines with the background facial configuration. UNIVERSITY OF CAPE COAST  FRAME SELECTION Considerations for Length of face Vertical and horizontal dimensions of the frame The roundness or squareness of the frame shape the coloration of the frame front. UNIVERSITY OF CAPE COAST  FRAME SELECTION Vertical and horizontal dimensions of the frame- the width and depth of the frame (dimensions). Horizontal Width of frame – The proper width of the frame* can be gauged as approximately equal to the widest part of the skull’s facial bone structure. the widest bony part of the face is always used as the reference point. because excess body and face weight may cause the wearer’s features to appear to be set in toward the center of the face; a frame based on the width of the actual face rather than structure would cause the person to appear cross-eyed. This “rule” is subject to modification with style changes UNIVERSITY OF CAPE COAST  FRAME SELECTION Vertical Depth of frame- As a general rule, the longer the face, the greater the vertical depth (distance from the upper to the lower rim) should be to keep the frame proportional to the face. The shorter the face, the smaller the vertical depth. In other words, a deeper frame is more complimentary to a long face, while a narrower frame lends itself more easily to a wide face. In this sense, the frame “covers” part of the face and covering more of a long face gives the illusion of reducing its length. UNIVERSITY OF CAPE COAST  FRAME SELECTION Roundness or squareness of the frame shape This deals with the angularity or roundness of the frame line (shape) as related to the angularity or roundness of the face and the eyebrow line. Square face- close to square shape Round face- close to round-oval shape UNIVERSITY OF CAPE COAST  FRAME SELECTION Coloration of frame front A darker, solid-colored frame will aid the effect of shortening a long face more readily than a vertically gradient frame. A solid frame seems to curtail the length of the face in the area extending from the dark lower rim to the chin. Short wide faces vertically gradient frames (draws the viewer’s attention to the upper part of the frame). a nylon cord frame with a dark upper portion. On a frame with a dark upper rim section and a lower rimless or nylon cord section, the reference point for face length is from the dark part of the frame at eyebrow level (the part that immediately catches our eye) to the bottom of the chin. a face lengthening effect, making them more compatible to the wide face. UNIVERSITY OF CAPE COAST  FRAME SELECTION Temple attachment Spectacle temples interject an artificial dividing line. The lower the line, the shorter the face appears; the higher the line, the longer it appears. Long faces- frame fronts with lower endpieces shorten the face. Wide faces- temples with high endpieces add length to the face. If the temple attaches high on the frame front, there is more facial area below this line, and the face appears lengthened and vice versa. Wide deeper temple creates shorter illusion and vice versa UNIVERSITY OF CAPE COAST TYPES OF SPECTACLE FRAMES UNIVERSITY OF CAPE COAST TYPES OF SPECTACLE FRAMES UNIVERSITY OF CAPE COAST TYPES OF SPECTACLE FRAMES UNIVERSITY OF CAPE COAST TYPES OF SPECTACLE FRAMES UNIVERSITY OF CAPE COAST TYPES OF SPECTACLE FRAMES UNIVERSITY OF CAPE COAST TYPES OF SPECTACLE FRAMES UNIVERSITY OF CAPE COAST TYPES OF SPECTACLE FRAMES UNIVERSITY OF CAPE COAST TYPES OF SPECTACLE FRAMES UNIVERSITY OF CAPE COAST TYPES OF SPECTACLE FRAMES UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from the lens. For this reason, this type of mounting can be used interchangeably with more than one pair of lenses for the same frame. Sun lenses, special purpose lenses, tinted lenses could then be used interchangeably with the patient’s regular lenses Notches are now more often used in combination with drilled holes in rimless mountings to lend stability to the mounting. UNIVERSITY OF CAPE COAST  TYPES OF SPECTACLE FRAMES Balgrip mountings secure the lens in place with clips attached to a bar of tensile steel that fits into a nasal and a temporal notch on each side of the lens. The lens can be easily removed by pulling the clips back from t