ABO Optical Terminology Flashcards

Questions and Answers

What does Single Vision correct?

Only distance vision

One distance (correct)

Only near vision

Multiple distances

What does Multifocal lenses do?

Only used for distance

Corrects for one distance

Only used for reading

Corrects with two or more prescriptions (correct)

What is a Bifocal lens?

A lens having two focus strengths.

What does a Trifocal lens pertain to?

Having three focus strengths. Signup and view all the answers

What is the purpose of Calculating Prismatic Effects?

Difference in edge thickness in an optical lens. Signup and view all the answers

What is the formula given in Prentice's Rule?

P = hcm x D Signup and view all the answers

What does Vertical Imbalance refer to?

Difference in vertical prism power at the reading level in a pair of lenses. Signup and view all the answers

What factors are involved in the minimum blank size formula?

ED + 2(d) + 2mm Signup and view all the answers

What does ANSI stand for?

American National Standards Institute. Signup and view all the answers

What is the role of the FDA?

Responsible for determining if a food or drug is safe. Signup and view all the answers

The distance between lenses is referred to as ______.

DBL Signup and view all the answers

Study Notes

Optical Terms and Definitions

Single Vision: Corrects vision for one distance only.
Multifocal: Lenses that correct vision with two or more prescriptions.
Bifocal: A lens with two different focus strengths for viewing at different distances.
Trifocal: A lens with three different focus strengths.

Optical Measurements and Instruments

Calculating Prismatic Effects: Achieved by altering edge thickness during lens surfacing or by de-centering the optical center.
Lensmeter: An instrument for verifying eyeglass prescriptions and marking lenses.
Lens Measurement Devices: Includes lens clocks, calipers, millimeter rulers, and circumference gauges for accurate measurements.
Digital Measurement System: Provides digital readings for measurements such as pupillary distance (PD) and segment height.

Prisms and Compensation

Compounding Prism: Combining two or more prisms in various configurations (BI & BI, BO & BO, BU & BD).
Cancelling Prism: Specific combinations like BI & BO or BD & BD that neutralize prism effects.
Prentice's Rule: Formula (P=hcm x D) calculates the prism created based on lens movement and power in the error meridian.
Vertex Compensation: When a plus lens is moved away from the eye, it appears to gain plus power.

Centration Techniques

Horizontal Centration: Measured using pupillary distance (PD).
Vertical Centration: Measured using the optical center (OC).
Centration Formula: Calculated as Given PD/OC - Human PD/OC to determine lens positioning.

Lens Power and Measurement

Power in Oblique Meridians: Calculated using Dt= (sina)²x Dc +Ds to find the total power required considering both cylinder and sphere powers.

Hand Tools for Eyewear Adjustment

Screwdrivers: Different types designed for specific tasks, like the scratchless screwdriver for delicate lenses.
Pliers: Various pliers such as lens axis pliers and temple angling pliers are used to adjust frame fittings without damaging them.
Files: Used for different purposes including filing plastic frames and screw heads.

Frame and Face Shape Considerations

Frame Fit: Importance of balance and comfort for various face shapes (e.g., larger frames for inverted triangle shapes).
Face Shapes Guidelines: Specific recommendations for frame types based on face shape to ensure proper aesthetics and comfort.

Regulatory Bodies

ANSI (American National Standards Institute): Develops voluntary consensus standards in the U.S.
ASTM (American Society for Testing and Materials): Focuses on developing testing standards.
EPA (Environmental Protection Agency): Federal agency for environmental protection programs.
OSHA (Occupational Safety and Health Administration): Standards for workplace safety and health.
FDA (Food and Drug Administration): Ensures foods and drugs are safe for public use.
FTC (Federal Trade Commission): Protects consumers from deceptive advertising.

Exam and Measurement Techniques

Measuring Segments:
- Bifocal: Measure from the bottom lid to the frame bevel.
- Trifocal: Measure from the lower edge of the pupil to the frame bevel.
- Progressive: Measure from the center of the pupil to the bottom of the frame.
Key Measurements:
- A and B measurements: Horizontal and vertical depth of frames, respectively.
- DBL: Minimum distance between lenses.
- ED: Effective diameter determined by the longest radius of the lens.

Frame Fitting Considerations

Bridge Pressure: Weight distribution on the nose, affecting comfort.
Ear Pressure: Critical for achieving comfort through correct adjustment.

Additional Terms

Datum Line: Reference point for lens measurements.
Minimum Blank Size Formula: Helps determine the size of lens needed based on the effective diameter.
Fitting Triangle: Proper fitting should touch three key points for balanced pressure distribution on the face.

Description

This quiz consists of flashcards that cover essential optical terminology used in lens prescriptions. Each card defines a key term related to vision correction, including single vision, multifocal, bifocal, and trifocal lenses. Test your knowledge on these important concepts relevant to optics and optometry.