COT Low Vision and Optical Aids 4

Question 1

A patient with a central scotoma due to macular degeneration is being taught eccentric viewing. Which direction should they typically be instructed to look to use their preferred retinal locus (PRL)?

Accepted Answer

Slightly to one side of the target

Answer

Patients with central scotomas use eccentric viewing by shifting their gaze so that the image falls on a functioning area of the retina peripheral to the scotoma, which is typically to one side of the target.

Question 2

Which low vision aid is MOST appropriate for a patient who needs to read price tags and labels while shopping?

Accepted Answer

Hand magnifier

Answer

A hand magnifier is most practical for spot-reading tasks like price tags and labels because it is portable, easy to use briefly, and requires no special positioning.

Question 3

When prescribing a telescope for a patient with low vision, the primary trade-off compared to a higher-magnification telescope is:

Accepted Answer

Reduced field of view

Answer

Higher magnification telescopes provide greater enlargement but significantly reduce the field of view, making scanning and mobility more challenging.

Question 4

A patient uses a 4X hand magnifier to read standard print. If the patient wishes to switch to a stand magnifier that delivers equivalent magnification, what should the COT consider about the stand magnifier's labeled power?

Accepted Answer

It may be labeled higher than 4X due to vergence differences

Answer

Stand magnifiers have a built-in object distance that produces divergent light, so patients using them with spectacles experience less net magnification than the labeled power; thus equivalent performance may require a higher-labeled stand magnifier.

Question 5

Which contrast-enhancement technique is MOST beneficial for a low vision patient with reduced contrast sensitivity?

Accepted Answer

Using yellow-tinted lenses or filters

Answer

Yellow or amber tinted lenses and filters enhance contrast by blocking short-wavelength (blue) light scatter, improving edge definition for patients with reduced contrast sensitivity.

COT - Certified Ophthalmic Technician Practice Test

COT - Certified Ophthalmic Technician Practice Test

COT Low Vision and Optical Aids 4