8 October 2020
The professor took her head in his hands and gently pointed her head in the direction of the letter chart. Her eyes lit up. “Oh, there it is”, and she promptly read the smallest size letters at the bottom of the chart.
Mrs Digby had advanced glaucoma that destroyed her peripheral vision. All that remained was a small tunnel of central vision with crispness that would have made many people envious.
I witnessed this as a final year optometry student on a clinical low vision placement – more than 30 years ago. Its effect left me a memory as fresh as if it had happened yesterday.
It is difficult to appreciate how someone else sees the world. It can be helpful if you can “see through someone else’s eyes”, particularly if you are designing products or environments that will be used by people who have vision impairment.
Here are 4 types of tools that can communicate the impact of vision impairment to people who are normally-sighted.
First-hand accounts
First-hand descriptions can be a powerful tool to help people with normal sight gain insight into vision impairment.
Some accounts are published in the medical peer-reviewed literature. For example, David Cockburn’s confessions of a colour blind optometrist1 gives an entertaining account of how his severe colour vision deficiency affected his service in the Navy during World War II and his career as an optometrist, as well as some practical examples of its effect while sailing, driving, painting, choosing clothes and identifying money. Although congenital colour vision defects, such as Cockburn describes, are not in the same league as more severe vision problems such as glaucoma, a range of acquired colour vision deficiencies do accompany many eye diseases (such as glaucoma, cataracts, age-related macular degeneration). Therefore, Cockburn's descriptions could be helpful for people with normal colour vision who are seeking to understand some of the frustrations of making colour errors.
One of my favourite written accounts is “Picking up Sunshine”, a self-published book by June Stephenson & Elizabeth Mansutti2. In it, Stephenson provides anecdotes of mistakes she has made due to her vision loss from Age-Related Macular Degeneration (AMD), as well as practical tips for maintaining independence. It’s a gem of a book for those who have been diagnosed with AMD and for their relatives and friends who need to understand what kind of help and assistance would be useful.
Digitally enhanced images
A picture paints a thousand words. Digitally altering a photograph or a video is a cost-effective method to illustrate vision impairment. For example, the image on the right-side simulates vision loss associated with cataract: loss of contrast, loss of visual acuity and distorted colour perception:
