20/20 VISION

20/20 vision is a term used to express normal visual acuity (the clarity or sharpness of vision) measured at a distance of 20 feet. If you have 20/20 vision, you can see clearly at 20 feet of what should normally be seen at that distance. If you have 20/100 vision, it means that you must be as close as 20 feet to see what a person with a normal vision can see at 100 feet.

20/20 does not mean perfect vision. It is only an indication of the sharpness or clarity of vision at a distance.