What is the best and worst vision a human has?!
Question: I heard that the best vision for a human was 20/8, and I was wondering if that was true. Also, I know that the worst vision is "legally blind" which is 20/200, but what I'm looking for is "eye measurements" such as 20/5000 or 20/10000, just as an example. And by the way, can someone really have vision like 20/10000?
Answers: I heard that the best vision for a human was 20/8, and I was wondering if that was true. Also, I know that the worst vision is "legally blind" which is 20/200, but what I'm looking for is "eye measurements" such as 20/5000 or 20/10000, just as an example. And by the way, can someone really have vision like 20/10000?
You are about right that 20/8 is the best vision. Some have claimed 20/5 but that seems to extreme to me since young healthy people who are corrected for higher order aberrations can't reach much better than 20/10. Yes you can have 20/10000. Its called blinder than a bat! Well the worst prescription I've heard of is -25 diopters which would probably be about 20/20000. So yeah, that's pretty bad. If you have 20/20 vision you can see something at 20,000 feet what a 20/20000 person can only see at 20 feet!!! So If you look at a mountain miles away it would take them about 20 feet to see the same thing! Wow that's horrible. Good think there's correction.
20 is normal and anything over 80 is poor but correctable and the worse is blindness of course. no not 10000.
blind at 200 is no sight,,how can it be worse?
Some humans have tested under 20/8 vision, but it's much more common to be able to achieve slightly better than average vision, around 20/15.
20/200 is legally blind, but you CAN have worse vision than that- a person's vision, once off standard eye charts (which go up to 20/400, usually) can be measured by counting fingers at specific feet, or if the person perceives hand motion, or if the person has light perception.
If someone has hand motion but no ability to count fingers even at 1 foot, the person has 20/8000 uncorrected vision. Beyond that, since the vision is entirely useless, it's not worth measuring.
The worst vision is known as NLP, which means no light perception. The next level better than that is LP which means light perception, ie you can only see whether the lights are on or off. Better than that is HM for hand movements, ie you are aware of movement in front of your face, then CF for count fingers - you can tell how many fingers someone is holding in front of your face. Then you move onto the measurements you described, realistically starting at about 20/2000.