Reading the eye chart is the first step to your eye exam.
An eye chart measures how well you see compared with the “normal” vision of the human eye, which is defined as 20/20. The top line on the Snellen Chart, “Big E” usually represents 20/200 vision.
When you read an eye chart, chances are that person testing you is paying attention to what you say, as well as how you say it. They will know if you are seeing clearly or are struggling and making guesses. It never pays to cheat on your eye test!
The eye chart that is most commonly used is the Snellen eye chart, which has been in use since 1860. This chart uses capital letters of descending sizes. Each row is related to the distance that someone with normal vision can see at a certain distance. If you can only read to the 20/40 line, that means that what you can see at 20 feet, what the normal eye can see at 40 feet away
The Jaeger eye chart or card, is the most common means of checking near vision. By holding a near vision card about 14” away from the eyes, patients are asked to read the smallest type. Just like the distance chart, there are rows of decreasing sizes. The measurement on the Jaegar chart is represented in a scale from J10 to J1. If you can read the smallest lines, your vision is J1, which is the equivalent of 20/20.
How well do I need to see to drive?
Although each state determines their specific requirements, generally 20/40 vision is needed to pass the driving test. If you need glasses to see 20/40, it will be indicated on your driver’s license.
After vision correction surgery, like LASIK or cataract surgery, you may be able to see well enough to have the vision correction restriction removed from your license.
What is legally blind?
If you cannot see any letters below the 20/200 line, even when wearing glasses or contacts, you are considered legally blind. People with poor vision that is correctable with glasses or contacts, are not considered legally blind, although they may not be able to function without their glasses on.
Report Any Changes
It’s important to report if you notice any changes in your vision. If your vision becomes blurry, if you see dark spots or distortions in your vision, see double images, or increased glare and halos, be sure to let your doctor know. That information can help to diagnose developing eye disease.
The Eye Test Chart is Just the START!
Just because you can read the 20/20 line on an eye chart that doesn’t mean that you can skip your next eye exam! There is so much more to having healthy eyes! At your comprehensive exam, our doctors examine the health of your eye, externally and internally. We also measure eye pressure and check for any signs of disease and vision loss.
How well do you see?
If it’s been more than a year since your last eye exam, call to make an appointment today!