COT Low Vision and Optical Aids 2

Question 1

A basic telescopic system used for distance low vision consists of which optical components?

Accepted Answer

An objective lens and an ocular (eyepiece) lens

Answer

A telescope uses an objective (front) lens to collect and focus light and an ocular (eyepiece) lens through which the patient views the resulting magnified image.

Question 2

What is the function of a 'reading cap' when added to a distance telescope?

Accepted Answer

To convert the telescope for near-vision tasks

Answer

A reading cap is a plus lens attached to the objective end of a telescope, changing its focus from distance to near and creating a telemicroscope for close work.

Question 3

Which electronic magnification device offers adjustable magnification, contrast reversal, and color settings to assist with reading tasks?

Accepted Answer

Closed-circuit television (CCTV) / video magnifier

Answer

A CCTV or video magnifier uses a camera and monitor to provide variable magnification, polarity reversal, and color adjustments that optical devices cannot offer.

Question 4

The preferred retinal locus (PRL) is best described as:

Accepted Answer

A peripheral retinal area spontaneously adopted for fixation when the fovea is damaged

Answer

The PRL is a non-foveal retinal location that a patient with macular disease spontaneously develops as the new fixation point to optimize remaining vision.

Question 5

Which illumination strategy is most beneficial for low vision patients performing near tasks such as reading?

Accepted Answer

High-intensity, directed task lighting positioned near the work surface

Answer

High-intensity task lighting directed at the work surface maximizes contrast sensitivity and visual performance for most low vision patients doing near tasks.

COT - Certified Ophthalmic Technician Practice Test

COT - Certified Ophthalmic Technician Practice Test

COT Low Vision and Optical Aids 2