Frederik's Friday Fact

Home Archive Ratings
Friday 13 Dec 2013: 20/20 vision
Normal (not: perfect) visual acuity is commonly defined as 20/20 vision, the metric variant is 6/6 vision. If you have 20/40 vision, it means you can read at 20 feet distance what a normal person would be able to read at 40 feet distance.

Rating: 0 1 2 3 4

Copyright FFF