Skip to main content

Our practice is right by Target & Rosa’s Café at 4109 North Midland Dr. Midland, TX 79707

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!

x

The pandemic of coronavirus (COVID 19) continues to spread endangering many of us who call Midland/Odessa home. While the number of cases in Texas is growing rapidly, so far there are few cases in our area. At Vision Health Specialties it is our goal to keep it that way.

Because eye care by necessity requires close contact between workers and patients, the Center for Disease Control along with other eye care specialty organizations recommend that during this critical period eye doctors suspend routine vision examinations. In complying with this, Vision Health Specialties will terminate routine eye care beginning Monday, March 23‎rd until Monday, April 20th. We will be open from 9:00 till 4:00 PM during this period of time with a small staff to handle urgencies such as red eyes, corneal ulcers, uveitis, abrasions, sudden increases in floaters, or flashes, and foreign bodies in the eye. Please call our office before coming in. Furthermore, those who have traveled to China, Italy, South Korea, Japan, Iran, or the state of Washington, California, New York, Louisiana and/or other affected areas, as well as those who have respiratory disease, and/or fever, will be referred to the emergency department of Midland Memorial Hospital where they are equipped to handle those at risk of coronavirus.