Visual acuity is commonly tested with the help of different eye charts, as this enables optometrists to determine how well you can actually see. The most popular chart used for testing vision acuity is the Snellen chart, which has letters of different sizes. The chart is set at 20 feet from the patient when the eye test is taken, and this is where the commonly known term of 20/20 vision comes in.
The term 20/20 vision should not be thought as “perfect” but as “normal” vision. Here are some quick indicators and facts that may explain the vision spectrum:
- 20/20 is the standard set as good, normal vision.
- 20/15 is even better and is quite common….
- 20/10 is less common, but not all that rare.
- 20/8 is the best recorded human vision possible.
- A hawk supposedly has 20/2 vision, which is the best in the animal kingdom.
- 20/10 means you can see at 20 feet what a person with good normal vision can see only when they are 10 feet away.
- The longest distance the human eye can see clearly is 20 feet away.
So what is 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 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 normal vision can see at 100 feet.
20/20 does not necessarily mean perfect vision. 20/20 vision only indicates the sharpness or clarity of vision at a distance. There are other important vision skills, including peripheral awareness or side vision, eye coordination, depth perception, focusing ability and colour vision that contribute to your overall visual ability. Some people can see well at a distance, but are unable to bring nearer objects into focus. This condition can be caused by hyperopia (farsightedness) or presbyopia (loss of focusing ability). Others can see items that are close, but cannot see those far away. This condition may be caused by myopia (nearsightedness).
How can you test your vision?
A comprehensive eye examination by Insight Optometrists can determine your ability to see and advise you of the next steps should your eyes need some form of treatment. We can prescribe glasses, contact lenses or a vision therapy program, so please contact us today to arrange an appointment for your eye test.