What is Vision (Snellen Chart) test?

The Snellen test uses a chart of letters or symbols. A visual acuity test is an eye exam that checks how well you see the details of a letter or symbol from a specific distance.

What the Vision (Snellen Chart) test used for?

You may need an eye exam if you feel you’re experiencing a vision problem or your vision has changed. A visual acuity test is one part of a comprehensive eye exam.

How is the procedure performed?

During the test, you’ll sit or stand a specific distance away from the chart and cover one eye. You’ll read out loud the letters you see with your uncovered eye. You’ll repeat this process with your other eye. Typically, your doctor will ask you to read smaller and smaller letters until you can no longer accurately distinguish letters.

What will be the results interprets?

Visual acuity is expressed as a fraction, such as 20/20. Having 20/20 vision means that your visual acuity at 20 feet away from an object is normal. If you have 20/40 vision, for example, that means you need to be 20 feet away to see an object that people can normally see from 40 feet away. If your visual acuity is not 20/20, you may need corrective eyeglasses, contact lenses, or surgery. You might also have an eye condition, such as an eye infection or injury, that needs to be treated. You and your doctor will discuss your test results as well as any treatment or correction that might be necessary.