What does 20/20 mean?
20/20 vision is a term used to descibe normal vision for a distance of 20 feet. The top number is the distance at which you can see the letters, and the bottom number the distance at which the average person can see them. For instance, if you have 20/20 vision, you can see clearly at 20 feet what should normally be seen at 20 feet. If you have 20/100 vision, it means that you must be as close as 20 feet to see what a person with normal vision can see at 100 feet.