Low Vision and Optical Aids Flashcards
7 cards from real COT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Low Vision and Optical Aids flashcards as text
A bioptic telescope is prescribed primarily to assist with which visual task?
Answer: Brief 'spotting' tasks such as reading street signs and traffic signals
Bioptic telescopes are mounted high in the spectacle carrier and used for brief spotting tasks (signs, signals) while routine vision is maintained through the carrier lens below.
Which optical device can be mounted on spectacles to redirect images from a blind visual field area into the patient's seeing field?
Answer: Fresnel prism
Fresnel prisms attached to spectacle lenses shift images from the hemianopic or sector-loss field into the functional seeing field, providing field expansion.
In a Galilean telescope, the eyepiece (ocular) lens is:
Answer: A concave (minus) lens
A Galilean telescope uses a concave (minus) lens as the eyepiece and a convex (plus) lens as the objective, producing an erect, upright image without requiring inverting prisms.
What is the primary practical advantage of a hand-held magnifier over spectacle-mounted high-plus lenses for certain low vision patients?
Answer: It allows the patient to vary the working distance and is convenient for brief or intermittent tasks
Hand magnifiers allow flexible working distance and are easy to use for brief tasks, unlike spectacle magnifiers that demand a strict, short focal distance at all times.
When prescribing progressively higher-plus reading additions for a low vision patient, the key optical trade-off is:
Answer: Greater image magnification but a progressively shorter working distance
As plus power increases, focal length shortens, requiring reading material to be held progressively closer, which can limit comfort and practical use.
Which of the following is an example of a non-optical low vision aid?
Answer: Large-print books and bold-line writing paper
Non-optical aids such as large-print materials, bold-line paper, and typoscopes improve task performance by modifying the environment rather than using optical magnification.
What is the purpose of a typoscope in a low vision rehabilitation program?
Answer: To isolate a single line of text, reducing surrounding glare and improving contrast for reading
A typoscope is a black card with a slot that frames one line of text at a time, blocking surrounding white page glare and enhancing contrast to improve reading performance.