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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!

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a3ef93d0 34de 453f b5f4 5ffd895a5f85 (1)A Letter from Dr. Ben Giddens

Hello friends, I have retired!

I had 37 years of good fun in Georgetown and loved the gift of meeting so many warm and friendly people! I am very sorry that I didn’t have the time to chat with everyone about my exact plans, and felt guilty over that at times. It was not an easy task. If anyone wants, or needs to contact me, please send an email to my office and I will reply.

I am 66 years old and still feel like I am in good health. My wife died of cancer in 2021 but I have good friends and family and a fun life. I recently moved back to Toronto which is where I grew up as a teenager. I have an active outdoor life and have many ski trips and travel plans in front of me. Lots of interests and activities to explore with an overriding sense that I am a lucky guy. I am also a grandfather now.

I have always tried to employ staff and optometrists who have a heart. I think that is where the office is at today and I hope it continues. Everyone knows their work, and the heart matters.

Ben.