# How do you define "legally blind?" **URL:** \ **Category:** Factual Questions\ **Created:** [July 20, 2002, 6:44pm UTC](https://boards.straightdope.com/t/how-do-you-define-legally-blind/119998 "2002-07-20T18:44:07Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![scott\_evil](https://avatars.discourse-cdn.com/v4/letter/s/91b2a8/32.png) [@scott\_evil](https://boards.straightdope.com/u/scott_evil)\ **Post date:** [July 20, 2002, 6:44pm UTC](https://boards.straightdope.com/t/how-do-you-define-legally-blind/119998/1 "2002-07-20T18:44:07Z")
My mother tells me her father was declared (?) legally blind. He wore thick glasses and all. So this morning, I went to the store wearing just my (non-prescription) sunglasses - no contacts, no glasses. I was able to function, because I was in a familiar area, but the question came upon me: am I legally blind? Without contacts or glasses, I can only see about a foot in front of me, at best (maybe even just six inches). Everything else is shapes and colors. I could certainly not drive or go to work without my contacts in. Also, I’ve been having problems reading things, so I have to get up close to whatever I’m reading. Do I need reading glasses now? I’m only 30. That would be sad. ---
**Author:** ![barbitu8](https://avatars.discourse-cdn.com/v4/letter/b/839c29/32.png) [@barbitu8](https://boards.straightdope.com/u/barbitu8)\ **Post date:** [July 20, 2002, 6:50pm UTC](https://boards.straightdope.com/t/how-do-you-define-legally-blind/119998/2 "2002-07-20T18:50:37Z")
“Without contacts or glasses…” is the key. One is legally blind if his or her best \*\*uncorrected \*\* vision in the \*\* better \*\* eye is 20/200 or worse. As long as your vision in one of your eyes is corrected to better than 20/200, you are not legally blind, unless you have a very severe restriction of field vision (tunnel vision). The formula for computing whether someon who has vision in at least one eye correctable to better than 20/200 but who has tunnel vision is legally blind is quite complicated. I can look it up if you insist. You have trouble reading even with your glasses on? Perhaps you need a stronger prescription. It would be very unusual for you, at age 30, to have presbyopia; however, you really should see your eye doctor. ---
**Author:** ![barbitu8](https://avatars.discourse-cdn.com/v4/letter/b/839c29/32.png) [@barbitu8](https://boards.straightdope.com/u/barbitu8)\ **Post date:** [July 20, 2002, 7:00pm UTC](https://boards.straightdope.com/t/how-do-you-define-legally-blind/119998/3 "2002-07-20T19:00:55Z")
OK, I had a few moments, so I dug up the tunnel vision stuff: Contraction of peripheral visual fields in the better eye. A. To 10° or less from the point of fixation; or B. So the widest diameter subtends an angle no greater than 20°; or C. To 20 percent or less visual field efficiency. Loss of visual efficiency. Visual efficiency of better eye after best correction 20 percent or less. (The percent of remaining visual efficiency=the product of the percent of remaining central visual efficiency and the percent of remaining visual field efficiency.) ---
**Author:** ![scott\_evil](https://avatars.discourse-cdn.com/v4/letter/s/91b2a8/32.png) [@scott\_evil](https://boards.straightdope.com/u/scott_evil)\ **Post date:** [July 20, 2002, 7:03pm UTC](https://boards.straightdope.com/t/how-do-you-define-legally-blind/119998/4 "2002-07-20T19:03:58Z")
All I can say is that without contacts or glasses, I couldn’t find my way around town. I was able to go to the store because it’s a familiar route. However, were I to come across anyone I knew, I wouldn’t recognize them, no matter how familiar. As for reading glasses, much as I’d hate to have to have to use them, I’ll consult my eye doctor. Thanks. ---
**Author:** ![Profane](https://avatars.discourse-cdn.com/v4/letter/p/e47774/32.png) [@Profane](https://boards.straightdope.com/u/Profane)\ **Post date:** [July 20, 2002, 7:17pm UTC](https://boards.straightdope.com/t/how-do-you-define-legally-blind/119998/5 "2002-07-20T19:17:48Z")
> [@](#): > > \*Originally posted by scott evil \* > \*\*All I can say is that without contacts or glasses, I couldn’t find my way around town. I was able to go to the store because it’s a familiar route. However, were I to come across anyone I knew, I wouldn’t recognize them, no matter how familiar. > \*\* My best friend, who is legally blind is like this with his glasses on, if that gives you a better idea. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [July 20, 2002, 8:24pm UTC](https://boards.straightdope.com/t/how-do-you-define-legally-blind/119998/6 "2002-07-20T20:24:00Z")
What I want to know is how does one know if he is legally bald. ---
**Author:** ![Ringo](https://avatars.discourse-cdn.com/v4/letter/r/779978/32.png) [@Ringo](https://boards.straightdope.com/u/Ringo)\ **Post date:** [July 20, 2002, 8:29pm UTC](https://boards.straightdope.com/t/how-do-you-define-legally-blind/119998/7 "2002-07-20T20:29:41Z")
Well **sailor** , I guess that would depend on to what degree it’s correctable. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [July 20, 2002, 8:38pm UTC](https://boards.straightdope.com/t/how-do-you-define-legally-blind/119998/8 "2002-07-20T20:38:25Z")
The president of the hair club for men told me they don’t do miracles and referred me to the Pope in Rome as my only hope.