Skip to main content
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!

500px

Call for an Appointment, We are open!

We are making special arrangements with the current public health concerns. When you call TSO Katy Fry, we will space your appointment time to be mindful of social distancing and your personal comfort.

TSO Katy Fry is here for your vision care. We are aware of your concerns and are taking extra precautionary action for your protection and safety. We carefully sanitize all surfaces, including equipment, frames and supplies, frame boards, desks, and keyboards.

When you schedule your eye exam appointment, you can have the extra confidence that you will be safe and comfortable at Texas State Optical.

Welcome to Texas State Optical Katy Fry

 
Appointment Form

Call (713) 322-6526 ▸

Take Me There

Welcome to Texas State Optical Katy Fry

Welcome to Texas State Optical Katy Fry

Welcome to Texas State Optical Katy Fry

Make an Appointment with:

Our Location

1245 N Fry Rd, Ste A
Katy, TX 77449