What Does it Mean to Have 20/20 Vision?

I've always knew the phrase "20/20 Vision" meant that you were support to have 'normal' vision but I never knew what the numbers meant...until now!

According to AllaboutVision.com -

"Visual acuity is usually measured with a Snellen chart. Snellen charts display letters of progressively smaller size. "Normal" vision is 20/20. This means that the test subject sees the same line of letters at 20 feet that person with normal vision sees at 20 feet."

If your second number is larger than the first, you are considered to be nearsighted or Myopic where things get clearer the closer to get to them. In the reverse, if your second number is smaller than the first, you are hyperopic or farsighted where things get clearer the further away they are. Like when you see people holding things at arms length to read them!

I'm slightly nearsighted (and getting worse every year) and about due for another eye exam