What is 20/20 vision? What does it mean to your eyesight? Many people often wonder what 20/20 vision is when they are getting their eyes examined or have a problem seeing well. When thinking about 20/20 vision, it is easiest to think of these numbers as distance or the feet from which a person can typically see. For instance, you go to the eye doctor, and he or she has you sit in a chair or stand on a line to read a chart with letters that get increasingly smaller as you go down the list. The place you stand or sit is 20 feet from the chart. This is where the first 20 comes from in normal vision. A person that can read the entire list of letters to the bottom has regular or normal vision. This is where the second 20 comes in regarding vision.
What does it mean when a person has 20/40 or 20/80 vision? When a person can only read halfway down the chart, they are considered to have 20/40 vision because they need to be 10 feet away from the chart to see the same thing that a person with normal vision can see from 20 feet. The 40 comes from the 20 being divided by half the distance. Someone who has 20/80 vision may only be able to read the first two or possibly some of the third lines on the eye chart. To get the 80, the 20 is divided by one-quarter of the distance because a person with that level of vision would need to sit or stand five feet away from the chart to read every line.
So, what is 20/20 vision? 20/20 vision means that a person can see anything clearly from 20 feet away from where they are located. People who can see things close to them, but not 20 feet away are considered nearsighted. Those that can see better at 20 feet than they can with things that are close to them have farsighted vision. This does not mean that the person has to have glasses, and it means that they may need to sit closer to the front of a classroom or hold a book up closer to their face than others to see clearly. Sometimes people with 20/20 vision need glasses because they cannot sit closer or hold things closer to them to see perfectly. Often these people are given reading glasses to help them get sharper vision. An expert eye specialist can help clear up any questions people may have about 20/20 vision.