How to Take the Snellen Eye Test

If you have had a routine doctor's exam, you are probably familiar with the Snellen eye chart. It is the chart that hangs in the office with the big letter "E" on top that the doctor uses to test your vision. The test is a quick and easy way to see if you may need to follow up with a more specialized eye doctor with for further tests. It may be rudimentary, but the Snellen eye test can help determine if you need glasses or more focused eye care.

Things You'll Need

• Snellen eye chart
• Tape measure

Show More

Instructions

• 1

  Hang the Snellen eye chart on a flat wall. Measure 20 feet away from wall and mark area with a line. Stand behind the line.

• 2

  Remove glasses and contacts. Ask someone to stand at the eye chart to verify your readings. Cover one eye with your hand and read the smallest line you can. Make note of which line you read with that eye; you can miss up to two letters per row to score that row for the test. Repeat the procedure with the other eye.

• 3

  Determine your visual acuity by reading the fractions next to the lines on the eye chart. Find the fraction next to the smallest line for which you tested no more than two letters missed. The top number will always be 20 because that is the distance you stood from the chart, 20 feet; the bottom number is how far away a person with normal vision could have read that line. For instance, if the bottom number is 40, then a person with average vision could have read the line at a maximum of 40 feet away.