What does “20/20” mean? Can you see better than 20/20? What’s the Guiness Book of World Records for vision?
The layman’s explanation of 20/20 goes like this: it means that you can see the same details from 20 feet away as a person with normal vision. If you have to stand at 20 feet to see details that a normal person can see from 40 feet, then your vision is 20/40.
The more precise definition is this: 20/20 means that you can distinguish letters whose smallest details are only as large as 1 arc-second, or 1/60th of a degree this is equal to about 1/16th of an inch at 20 feet.
Some people can see better than 20/20. In fact, Olympic athletes in vision-dependent sports like archery and sharpshooting have an average visual acuity of 20/16.
However, at a certain point the wave-like nature of light limits your best possible visual acuity. Light bends slightly around the edges of your pupil: this is called the phenomenon of diffraction. It means that it is physically impossible to see better than about 20/8.
-Dr. Oliver Kuhn-Wilken
I think I have better than 20/8 vision . What if out can see the moisture content in the air ? Or cosmic dust that falls to the earth that looks like rain on a sunny day , or can see the heat vapor at comes from the human body , and other things that your not suppose to see . Let me know what your thoughts are ? Thanks
Went to the eye doctor today and read the chart with letters that get smaller and the doctor said I had 20 -10 eye vision