What is 20/20 vision?
When people talk about perfect eyesight, they often refer to it as ‘2020 vision.’ It’s the same note you can see next to the smallest line on an eye test. But, what does ’20/20′ actually refer to?
The test with which visual acuity is typically measured is called the ‘Snellen chart’ (which has an enormous ‘E’ at the top). The Snellen chart bases its readings on distance. It measures your vision against a ‘normal’ standard and assigns a number to you relative to that of the standard.
When you go into your optometrist for an eye exam, you’re placed 20 feet away from the chart. “20/20” refers to the distance at which you’re able to see relative to a ‘normal’ standard. According to the Eye Care Associates of East Texas:
“This means that the test subject sees the same line of letters at 20 feet that a normal person sees at 20 feet. 20/40 vision means that the test subject sees at 20 feet what a normal person sees at 40 feet. Another way of saying this is that a person with 20/40 vision has a vision that is only half as good as normal – or, objects must be at half the normal distance for him to see them. A person with 20/20 vision is able to see letters 1/10th as large as someone with 20/200 vision. However, the 20/15 vision is better than the 20/20. A person with 20/15 vision can see objects at 20 feet that a person with 20/20 vision can only see at 15 feet.”
So, it is possible to have a better than 2020 vision (although it is rare) and it’s, of course, possible to have less than average vision. Luckily, vision can be corrected with the use of glasses or contacts. If you’re unsure of your vision or haven’t had an eye exam in a while, it might be time to set an appointment. While less than 2020 vision isn’t disastrous (you can pass a Driver’s License exam with 20/40 vision), it’s still important to know where your vision level is and to take the necessary action to correct it.
A visit to your eye doctor is not only an excellent way to find out if you have a 20/20 vision. Seeing your optometrist is also an important part of maintaining and improving your overall health. Set an appointment with an optometrist today.