Skip to main content
Book an Eye Exam Call (804) 285-7638
eyeglasses-wall-display-on-a-slant
Home » Your Eye Health » Eye Exams » Common Tests » Snellen Chart

Snellen Chart

Hopefully by now, we’ve all seen one. The projected or wall-mounted Snellen eye chart, usually topped by the big letter “E”, is a common visual acuity test used to measure your sharpness of vision at multiple distances.
 
Arranged as a pyramid of sorts, the letters in the Snellen chart are specifically chosen and arranged to test your sharpness and clarity of vision at a baseline distance of 20 feet. During a visual acuity test, the Snellen eye chart is viewed as a projection, or mounted on a wall.
 
Handheld versions of Snellen charts are used for testing near vision as well.
 
By viewing or reading each line from top to bottom (with one eye covered at a time), your eye doctor can gain a general approximation of the quality of your visual acuity, or sharpness. Where a line of characters begin to become difficult to see is the approximate measurement of your vision.
 
The Snellen chart serves as a beginning—not an end—to a comprehensive eye examination.

What does “20/20” vision mean?

Snellen charts help to determine a baseline for your vision in each eye—a baseline typically measured against “20/20” vision. This means when you are 20 feet away from an object, you can comfortably see details that most people with normal vision can also see at 20 feet distance.
 
If you have 20/30 vision, that means what you see comfortably at 20 feet, can be seen by a person with “normal” vision at 30 feet. Your vision is weaker, in other words.
 
Conversely? In the rare instances where vision may test better than normal on a Snellen chart, a value of 20/10 vision means that you can see clearly from a distance of 20 feet, what a person with normal vision sees well at a distance of 10 feet. Make sense?
 
In fact, if you look closely at a Snellen eye chart, you’ll see the vision values associated with measuring your vision on the right or left side of each line of characters.
 

Special thanks to the EyeGlass Guide, for informational material that aided in the creation of this website. Visit the EyeGlass Guide today!

In an effort to reduce the spread of COVID-19, the CDC has recommended that all routine eye care be deferred until further notice.

For the safety of our patients, our team, and the community, P.E.C. is complying with that recommendation. We are currently rescheduling annual eye examinations for patients without problems.

Our doctors are continuing to see patients with urgent and emergent eye problems.

Temporarily, our office is open from 8 a.m. to 1 p.m. Monday - Friday.

Please call 804-285-7638 before coming to the office so that we can address your questions and concerns on an individual basis.

If you are picking up contact lenses or eyewear, we would be happy to bring them to your car. We can also mail your contact lens supply without shipping charges.

After business hours, if you have an eye emergency, please call 804-205-7628 to speak to one of our doctors.

Stay safe. We very much look forward to seeing you in the future.

Patterson Eye Clinic