2006-07-20 12:21:41 · 12 answers · asked by TS 2 in Health ➔ Other - Health
The notation of visual acuity is written as a fraction, with normal vision being 20/20 (twenty twenty vision). At a 20 foot distance, (the top number in the fraction, or testing distance), a person with normal vision should be able to read the small 20/20 line on an eye chart. The smallest line that you can read on the chart is your visual acuity.
If the vision is 20/10, it means that the vision is better than normal. A person with 20/10 vision can read a letter at 20 feet that a person with normal vision would have to come up to 10 feet to read.
The term 'perfect vision' has no specific definition. In general vision of 20/20 or better than 20/20 may be considered perfect vision as at these vision levels one would not need glasses etc for performing any activity - driving, watching movies etc. Therefore - both 20/20 as well as 20/10 vision can be regarded as 'Perfect Vision' in the sense that these people are not limited in any way as far as seeing is concerned. A person with 20/10 vision will see clearly at distances further than a person with 20/20 vision, but in real everyday life, there is hardly any activity wherein 20/10 vision is required.
2006-07-23 04:04:33 · answer #1 · answered by MD 2 · 0⤊ 0⤋
20/10
2006-07-20 12:26:31 · answer #2 · answered by claire nit 1 · 0⤊ 0⤋
20/20
2006-07-20 12:24:58 · answer #3 · answered by classychick 2 · 0⤊ 0⤋
20/20 is considered normal vision. 20/10 is twice as good. Perfect vision is about 20/5 which is the limit of resolution of photoreceptors in the retina and so called diffraction limit for the optical system of the eye. For all practical purposes 20/10 could be considered perfect.
There is also an issue of contrast and image quality: some people can read the 20/10 line on the letter chart, but their vision is not very good in terms of contrast, so that if the letters were gray on white instead of black on white they might only see 20/20 or worse. Contrast sensitivity depends on the optical quality of the eye.
2006-07-20 12:30:30 · answer #4 · answered by mityaj 3 · 0⤊ 0⤋
20/20 is normal good vision. 20/10 is exceptional vision and about as good as humans can see. I've heard of a half dozen people, Billy Bishop, WW1 fighter ace for one, that had 20/9. It would mean what he saw at 20 feet would be to normal people the save as 9 feet. No wonder he was an exceptional pilot.
2006-07-20 12:29:16 · answer #5 · answered by Rockvillerich 5 · 0⤊ 0⤋
20/20 is considered perfect, but 20/10 is even better.
2006-07-20 12:23:37 · answer #6 · answered by rockinout 4 · 0⤊ 0⤋
you were right 20/20
2006-07-20 12:23:32 · answer #7 · answered by michael_roberts95 2 · 0⤊ 0⤋
Average vision is 20/20 standard and that is what most people can see at. 20/10 means that your vision is sharper than average, in fact it is the highest possible vision without binocular aid.
2006-07-20 12:25:57 · answer #8 · answered by Michael 2 · 0⤊ 0⤋
20/20 IS PERFECT 20/10 IS EVEN BETTER, IS EXCEPTIONAL
2006-07-20 12:25:08 · answer #9 · answered by helper 6 · 0⤊ 0⤋
20/20 is you see good at 20' as "normal" people see, 20/10 is you see 20' as good as "normal" people see 10', perfect is 20/20. At least thats what my eye doctor told me.
2006-07-20 12:25:47 · answer #10 · answered by johnny swanberg 2 · 0⤊ 0⤋