BRS Low Vision Aids & Devices 3 — Questions and Answers
Question 1: A BRS is assessing a patient's reading speed with a low vision device. Which measure is the MOST clinically relevant indicator of functional reading success?
- Maximum magnification achievable
- Reading speed of at least 40–60 words per minute (Correct answer)
- Visual acuity better than 20/200 with the device
- Ability to read at a standard 40 cm working distance
Correct answer: Reading speed of at least 40–60 words per minute
A reading speed of 40–60 words per minute is considered a functional threshold that allows practical reading of everyday materials.
Question 2: When prescribing a microscopic spectacle lens for near work, what is the primary trade-off compared to a hand magnifier at the same power?
- Microscopic lenses are heavier and more expensive
- Working distance is greatly reduced, requiring the patient to hold material very close (Correct answer)
- Microscopic lenses provide less magnification at equivalent power
- Hand magnifiers always produce higher contrast images
Correct answer: Working distance is greatly reduced, requiring the patient to hold material very close
Microscopic lenses require very short working distances (often a few centimeters), which can be ergonomically challenging but frees both hands.
Question 3: Which feature of a head-mounted video magnifier (e.g., eSight, IrisVision) offers an advantage over traditional optical devices for patients with low vision?
- They require no training to use effectively
- They allow real-time digital image processing with adjustable contrast and color (Correct answer)
- They provide higher magnification than any optical device
- They are covered by all US insurance plans
Correct answer: They allow real-time digital image processing with adjustable contrast and color
Head-mounted electronic magnifiers offer adjustable contrast, color inversion, and digital zoom, providing customizable visual enhancement not possible with fixed optical lenses.
Question 4: A patient with macular degeneration and 20/400 acuity wants to watch television at 10 feet. Which device category is MOST appropriate?
- Handheld magnifier
- Bioptic telescope spectacles (Correct answer)
- Dome magnifier
- High-add reading glasses
Correct answer: Bioptic telescope spectacles
Bioptic telescope spectacles provide the distance magnification needed to view a television across a room, unlike near-focused magnifiers.
Question 5: What is the purpose of a typoscope when used as a low vision aid?
- To increase magnification of printed text
- To reduce glare and isolate lines of text for easier reading (Correct answer)
- To project text onto a larger screen
- To convert printed text to Braille
Correct answer: To reduce glare and isolate lines of text for easier reading
A typoscope is a black card with a reading window that reduces glare from white paper and isolates one line of text, improving contrast and reducing visual confusion.
Question 6: In the context of low vision rehabilitation, 'relative distance magnification' is achieved by:
- Using a telescope to enlarge distant objects
- Moving the object closer to the eye to make it appear larger (Correct answer)
- Increasing the font size of printed material
- Using image-processing software to enhance contrast
Correct answer: Moving the object closer to the eye to make it appear larger
Relative distance magnification occurs when an object is moved closer to the viewer, which increases its angular subtense and makes it appear larger without any optical device.
Question 7: Which scanning strategy is MOST important to teach a patient who has a dense inferior visual field loss when using a CCTV for reading?
- Always scan left to right across the full screen
- Position text in the upper portion of the screen to use the remaining superior field (Correct answer)
- Increase magnification to eliminate the need for scanning
- Use a reading stand to maintain a fixed head position
Correct answer: Position text in the upper portion of the screen to use the remaining superior field
Positioning text in the upper screen area places it within the patient's intact superior visual field, compensating for inferior field loss during reading.
BRS Low Vision Aids & Devices 3
A BRS is assessing a patient's reading speed with a low vision device.
Which measure is the MOST clinically relevant indicator of functional reading success?