When talking about vision, what do the numbers mean when you say "20:15, 20:20, etc.?

Question

You know when people say, I can see 20/20. And that is supposed to be perfect vision? What to those two numbers mean? Like for each eye you can see 20 feet or something in front of you? I saw someone say that the first number is what you see, and the second number is what the average person sees.

According to that, if you see 20/15. That means you can see 20 ft in front of you when the average person can only see 15 feet in front of them (meaning its better then perfect vision)

Am I right? My sister and I want to know. Thanks ahead of time.

Answer 1

20/20 means you see something that is 20 feet away as though it is 20 feet away.

20/40  means you see something 20 feet away as though it was 40 feet away.

Answer 2

yes you are correct

Answer 3

NOT QUITE...TGE

HE  LOWER THE SECOND NUMBER THE BETTER THE VISION ....20/20 WAS THOUGHT TO BE PERFECT BUT THERE ARE PEOPLE WHO HAVE TESTED AT 20/8.....ALSO HAWKS,WHO HAVE MUCH BETTER VISION THAN HUMANS,HAVE TESTED AT 20/2.  THE HIGHER THE SECOND NUMBER THE POORER THE VISION

Answer 4

You are correct.  It is your vision at 20 feet, compared to the average human's vision at 20 feet.  

So, 20/15 would be better than average.  

Star athletes in sports that require hand-eye coordination (like baseball) often have better than 20/20 vision.  

And there is a type of laser procedure, similar to Lasik, that can provide much better vision, sometimes as good as 20/8.  I have seen it profiled on TV, but can't remember the exact name.  This newer device does not require the patient to read a chart, instead the machine reads the shape of the eye, and automatically makes the alterations.

According to the report, some athletes with 20/20 vision undergo the procedure to gain a competitive advantage.

Answer 5

yup your right.