You’ve probably seen a chart such as this before during a routine eye exam. In the US, they’re usually placed 20 feet away from your eyes and colored in standard black and white.
There’s a popular disbelief that 20/20 vision is considered exceptional or above average. Surprisingly, that’s not the case. 20/20 vision is actually considered “normal” vision, meaning you can read at 20 feet a letter that most human beings should be able to read at 20 feet.
Eye charts can be configured in various ways, but generally, if during an eye test you can read the big E at the top but none of the letters lower than that, your vision is considered 20/200. That means you can read at 20 feet a letter that people with “normal” vision can read at 200 feet. In this country, you’re considered legally blind if your seeing distance with glasses or contacts on is 20/200 or worse.
Here are some more interesting vision facts that may give you a little perspective about your eyesight:
- To obtain a driver’s license: at least 20/40
- To become a pilot: mandatory 20/20
- Birds of prey: 20/5 or 20/4
- Dogs: 20/75 (again, meaning what we see at 20 feet, dogs can see at 75)
If you’d like to know your “vision number,” ask our Michigan Eye Institute doctors during your next visit!