OPTO101 Unit 4: Instruments in Optometric Practice PDF

UNIT 4: INSTRUMENTS IN OPTOMETRIC PRACTICE DR. IVAN MENDOZA-VELOSO Instructor REFRACTION 1. KERATOMETER 2. RETINOSCOPE PHOROPTER 3. TRIAL LENS & FRAME...

UNIT 4: INSTRUMENTS IN OPTOMETRIC PRACTICE DR. IVAN MENDOZA-VELOSO Instructor REFRACTION 1. KERATOMETER 2. RETINOSCOPE PHOROPTER 3. TRIAL LENS & FRAME A phoropter is an instrument comprised of 4. PHOROPTER cylinders, prisms, and lenses that measures the 5. AUTO-REFRACTOR eye's refractive error to help determine and eye 6. LENSMETER prescription. 7. VA CHART/OPTOTYPES Mounted all trial lenses into one instrument. KERATOMETER Keratometer or ophthalmometer is an instrument used to measure the anterior corneal curvature and the axis and extent of astigmatism. The process of these measurements is called keratometry. This is also a tool. AUTO-REFRACTOR An auto-refractor or optometer is an instrument that helps in the automated assessment of refraction. This is an alternative method of finding out the refraction error in contrast to the conventional refractive technique. RETINOSCOPE A handheld instrument called a retinoscope shines a beam of light into the eye. Retinoscopy is an exam technique that objectively measures the refractive error of the eye. LENSMETER A lensmeter or lensometer is an instrument used to verify the prescription of eyeglasses or spectacles. Determine the power of the lens that you are wearing or being dispensed using lensometer. TRIAL LENS & FRAME Set of different types of ophthalmic lens. It is used during refraction. spherical concave lenses spherical convex lens VA CHART/OPTOTYPES cylindrical lens The visual acuity chart is used to determine loose prism the smallest letters you can read on a Accessories standardized chart (Snellen chart) or a card held 20 feet (6 meters) away. Special charts are used when testing at distances shorter than 20 feet (6 meters). VA = Visual Acuity ETDRS = Early Treatment Diabetic Retinopathy Study VISUAL FIELD INSTRUMENTS A visual field test measures your peripheral vision, or how well you can see above, below and to the sides of something you're looking at. It's also called a perimetry test. -the general term of the instrument in perimetry of visual field test is called PERIMETER. OCULAR HEALTH EXAMINATION - more on the structure itself - Observe the structure if it's normal, with normal limits, if there’s alteration, if there is disruption, degeneration, or alteration from the normal eye and the eye you examine. 1. OPHTHALMOSCOPE 2. SLIT-LAMP COLOR VISION DEVICES 3. VISUAL FIELD INSTRUMENTS A color vision test measures your ability to tell 4. COLOR VISION DEVICES the difference among colors. If you don't pass this test, you may have poor color vision, or your doctor may tell you that you're color blind OR OPHTHALMOSCOPE deficient An ophthalmoscope is about the size of a flashlight. It has a light and different small lenses that allow the provider to view the back of the eyeball. BINOCULAR VISION EXAMINATION -test the binocularity of the eye, if they work SLIT LAMP well together. (1) A slit lamp is a microscope with a bright light -if they work well together you have binocular used during an eye exam. vision/binocularity (2) A slit lamp is an instrument consisting of a high-intensity light source that can be focused to 1. AMBLYOPSCOPE shine a thin sheet of light into the eye. 2. PRISM BARS -observe or evaluate an eye from external to 3. WORTH 4-DOT internal. 4. STEREOSCOPIC DEVICES AMBLYOPSCOPE An instrument for measuring the angle of a squint and assessing the degree to which a person uses both eyes together. -very useful in squinting -measure how strong is the miss alignment or degree of miss alignment OPHTHALMIC APPLIANCES & DEVICES 1. OPHTHALMIC LENSES SINGLE VISION DOUBLE VISION 2. CONTACT LENSES HARD CONTACT LENS SOFT CONTACT LENS RGP PRISM BARS 3. PRISMS The prism cover test has been in use for many MEASURING PRISM years for measuring ocular alignment. The RELIEVING PRISM measurements obtained are used for both DISSOCIATING PRISM calculating the amount of correction needed in ADVERSE PRISM strabismus surgery and monitoring any change in 4. LOW VISION AIDS ocular alignment with recovery from muscle MAGNIFIERS imbalance. TELESCOPIC AIDS OCULAR EXERCISES OPHTHALMIC LENSES Ophthalmic lenses are medical devices that correct vision problems for people whose eyes' focal points don't hit the retina WORTH-4-DOT The Worth Four Light Test (Worth's Four Dot test, W4LT) is a clinical test assessing binocular vision, including diplopia, suppression, and anomalous retinal correspondence (ARC). This simple test can be performed even on verbal children. CONTACT LENSES Contact lenses are thin, clear plastic disks you wear in your eye to improve your vision. -eyeball extension STEREOSCOPIC DEVICES Stereo depth perception tests are an effective and easy to use method of screening stereoscopic vision for all ages. Depth perception is your ability to see objects in three dimensions, including their size and how far away they are from you. PRISMS Ophthalmic Prisms are thin prism that can be combined with ophthalmic lenses to correct or relieve eye deviations. LOW VISION AIDS Low-vision devices are designed to improve visual performance in children with low vision, thus enabling academic and social adaptation.