Originally posted by: meltdown75
my brother has better than 20/20 and he doesn't wear glasses or anything - is that possible?
Yes.
Contrary to what most people believe, 20/20 is not perfect vision. It just means that the smallest discernable characters you could see at 20 feet away could be read by a normal person at 20 feet away also. Hence, 20/20 is average vision, not perfect (how would you define perfect vision anyway?)
So a person with 20/40 vision could only resolve something 20 feet away when an average person could do it at 40 feet away.
In your brother's case (let's say he has 20/10), his eyes can resolve something 20 feet away that a person with normal vision could only resolve at 10 feet away. So, your brother's vision is better than the average joe.
So having better than 20/20 vision is entirely possible. From what I understand, most fighter pilots have 20/15 to 20/10 vision without corrective lenses.