The eye chart, many times referred to as The Snellen Eye Chart, is a chart used to tell you how well you see, in comparison to how well other people see. It tells you whether or not you have “normal” vision. It is a standard for knowing whether or not you need glasses, how well you see in general, and can possibly make you aware of potential eye problems.
The eye chart tells you whether or not you have 20/20 vision. The chart tells you if you are twenty feet away from the eye chart, whether or not you can see as well as the average person who stands twenty feet away from the chart. If you can, then you are said to have 20/20 vision. If you have 20/40 vision, then you can see standing twenty feet from the eye chart, what the average person can see standing forty feet away from the eye chart.
Eye charts are used starting at a very young age. When a child is very young and does not yet know his or her alphabet, the eye chart is full of different sized E’s which are pointed in different positions, with some being sideways, others being upside down or backwards, and some being positioned correctly. The child is then asked by the person giving the eye test, to use his or her fingers to point in the direction the lines coming off the E’s are pointing. So, at a very young age, an eye chart is used to tell whether or not a child is having problems seeing normally.
Most people get their eyesight checked at a doctor’s office, or by an optician in a store that sells glasses, but it is possible to buy an eye chart at the store or to download an eye chart off the internet. These charts can be useful for following your vision, especially if you are having problems with your eyes, but they are not a substitute for having your eyes examined regularly by a professional, as professionals can see many things going on in your eyes that an eye chart cannot tell you, some of which can threaten your eyesight.
