AT for Visual Impairments
A majority of the population in the United States wears glasses, and for adults over 50, more that 80% wear some kind of corrective lens. At the same time, people living with “vision impairment,” vision that is 20/40 or worse even with correction, is increasing in the U.S. and is expected to reach 8 million people by 2050. As the population ages, even people with corrected/correctable vision may rely more heavily on assistive technologies to assist with their vision, making this kind of AT some of the most widespread.
There are many conditions that can lead to visual impairment, some preventable, some not. Different conditions lead to different types of visual loss. For example, retinitis pigmentosa, a hereditary retinal disease, dims sight from the “outside in” with the focal point remaining clear until the disease is very advanced. Macular degeneration, on the other hand, begins with a dimming of vision at the focal point and moves outward toward the peripheral vision.
Because visual impairment can vary in its cause and its effect and can impact people at any stage of life, it is impossible to generalize to only a few assistive technology solutions. A person who is born blind and a person who becomes blind over time have had very different life experiences and may require very different AT, even if, in the end, they are both blind.
It is important to understand that most people who are blind retain some light sensitivity. This is an important fact because it informs assistive technology for this population. Visual markers like high-contrast text or physical room elements (eg: a very dark floor contrasting with a white wall) can be useful to a wide variety of people with visual impairment, as can small and very bright lights such as LED lights used to mark the placement of important room elements.
Other common AT for this population include:
- Large print books, signs, documents, calculators, etc
- Magnifying devices and software
- Guide dogs and white canes
- Voice recorders and players
- Screen and text readers
- Human guides
- Voice-only versions of digital devices
- Tactile representations
- Augmenting video tracks with audio description
Some people who are blind are Braille readers as well, and for this population there are a number of other AT available:
- Perkins Braille “typewriter“
- Digital Braille embossers
- “Swell paper” systems for printing Braille and tactile graphics
It is important to remember that for many of the AT for visual impairment to work, the underlying digital file needs to be supportive of the application. Digital documents that have been created without good software use will create files that will not translate well into Braille or audio formats. It is very important to focus on accessible document creation.