low_vision_flashcards
What is BlindSquare?
An app that describes the environment and announces points of interest as you travel.
What does the iDentifi app do?
Provides voiceover descriptions for objects in the camera screen.
How does the Be My Eyes app assist visually impaired users?
It connects them with sighted volunteers for assistance.
What are tints used for in low vision aids?
Dark tints for albinism or RP, and yellow filters for contrast sensitivity in AMD.
What is the purpose of caps or visors in non-optical low vision aids?
To reduce excess glare and reflections.
How is extra illumination used for patients with AMD, glaucoma, DR, or RP?
It enhances visibility by providing additional light.
For which conditions is reduced illumination used as a low vision aid?
For conditions like albinism, aniridia, and cataracts.
What is an advantage of stand magnifiers?
They are hands-free, which is great for hobbies like knitting.
What is a disadvantage of stand magnifiers?
Fixed focus requires the object to be held at a specific point for a clear image.
What is an advantage of dome magnifiers?
They enlarge text instantly and rest on the page.
What is a disadvantage of dome magnifiers?
They can be heavy and fiddly, making them difficult for patients with arthritis.
What is an advantage of hand magnifiers?
They are portable, lightweight, and available in many strengths.
What is a disadvantage of hand magnifiers?
They must be held at a very specific focal point to be effective.
How can patients expand their field of view when using a stand or hand magnifier?
By moving closer to the magnifier once the image is in focus.
What is an advantage of a high plus spectacle prescription for reading?
It may replace a magnifier, providing a convenient option.
What is a disadvantage of a high plus spectacle prescription for reading?
The lenses can be very heavy.
What is a Galilean telescope made up of?
Two lenses: a convex (plus) lens and a minus lens.
What is an advantage of a Galilean telescope?
It widens the visual field, useful for patients with peripheral vision loss.
What is a disadvantage of a Galilean telescope?
The quality of the visual image and detail may be poor.
What is a Keplerian telescope made up of?
Two convex (plus) lenses and a prism to reverse the inverted image.
What is an advantage of a Keplerian telescope?
It provides a larger visual field and better optical image quality than Galilean telescopes.
What is a disadvantage of a Keplerian telescope?
It is longer, heavier, and more expensive than a Galilean telescope.
How do you calculate the magnification power of a lens?
Magnification = F/4, where F is the dioptre power.
How do you calculate the focal length of a lens?
Focal Length (m) = 1/F, where F is the dioptre power.
How do you determine the magnification needed based on current and desired reading ability?
Magnification = Current N reading ability / Desired N reading ability.
How does acuity reserve help calculate magnification for fluent reading?
Acuity reserve is calculated at 2:1, meaning the patient must spot-read text half the size of the fluent reading goal.
How do you calculate magnification with acuity reserve?
Magnification = Current reading ability / (Desired reading ability ÷ 2).
What are some non-optical low vision aids to manage glare?
Caps, visors, and tints for various conditions such as albinism and AMD.
What is the difference between a Galilean and Keplerian telescope?
Keplerian provides a better image but is heavier and more expensive, while Galilean is lighter and cheaper with lower image quality.
What is the typical magnification power of a 10 dioptre lens?
2.5x (calculated as 10/4 = 2.5x).
Why is lighting important for patients using low vision aids?
Proper lighting enhances contrast and improves reading ability.
What is a key disadvantage of dome magnifiers for some patients?
They may be heavy and difficult to use for patients with arthritis.
What type of lighting is recommended for patients with albinism or cataracts?
Reduced illumination is typically recommended.
Why is a Galilean telescope sometimes preferred over a Keplerian telescope?
It is lighter and less expensive, despite having a lower image quality.
How does using a hand magnifier differ from a dome magnifier?
A hand magnifier is portable and lightweight but must be held at a specific focal point.
What non-optical aid is commonly used to enhance reading contrast for patients with AMD?
Extra illumination.
What low vision aid can be helpful for hands-free use in hobbies?
Stand magnifiers.
What is the magnification power of a 5 dioptre lens?
1.25x (calculated as 5/4 = 1.25x).
What type of telescope provides a wider visual field for patients with peripheral vision loss?
Galilean telescopes.
What is a non-optical LVA used to reduce glare in patients with retinal conditions?
Caps or visors.
How can you improve the reading ability of a patient with low vision?
By providing proper lighting and contrast along with the appropriate magnifier.
What advantage does a Keplerian telescope offer over a Galilean one?
It provides a larger visual field and better image quality.
How do you calculate the focal length of a 10 dioptre lens?
0.1 meters or 10 cm (calculated as 1/10 = 0.1).
What is an example of assistive technology for low vision?
Be My Eyes, which connects visually impaired users with sighted volunteers.
How does the BlindSquare app assist low vision patients?
It describes the environment and announces points of interest as the user travels.
