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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!

Dear TSO Patients,

We will continue taking precautions at our office.

-Our staff will be wearing masks. We also ask that any patient coming to our office wear a mask.

-Patients will call our office when they arrive to check in. Patients will be asked to stay in their cars until we are ready to start the exam.

-Patients’ temperature will be taken upon entry, and they will be asked to sanitize their hands.

-To reduce the amount of people in the office, only the patient is allowed into the exam room unless the patient is a minor or need additional assistance.

-Exam rooms, credit card terminals, counter tops, etc. will be wiped down between patients.

-Patients should call when they come for pickup of glasses and contact lens orders, we will deliver to them curbside.

-Frames that have been handled in the optical will be placed into a tray, and sanitized before they are returned to the frame board.

-Our office will continue to do curbside dispensing for eyeglasses and contact lenses.

Thank you for your support.

Drs. Hassett, Noorali, and Your TSO Staff

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