You’re probably familiar with the Snellen Eye Chart. Although largely replaced by the LogMar Chart in recent years, the Snellen Chart, developed in 1862, was long the standard way for measuring visual acuity. Visual acuity is described as the ability to see detail, or the resolution of your vision. It is measured in angles, and is dependent on the position of visual receptors in the retina. That big “E” on the eye chart was designed with a careful geometry to accurately measure those angles at a particular distance.

The video below takes the Snellen Chart and demonstrates its functionality at scale, measuring visual acuity across the San Francisco Bay.

David Crotty

David Crotty

David Crotty is the Editorial Director, Journals Policy for Oxford University Press. He serves on the Board of Directors for the STM Association, the Society for Scholarly Publishing and CHOR, Inc. David received his PhD in Genetics from Columbia University and did developmental neuroscience research at Caltech before moving from the bench to publishing.

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Discussion

2 Thoughts on "Design Matters: The Snellen Eye Chart"

I so enjoyed this! Will share with the ophthalmologist in my life. Thanks!

Hi,
This is well done, thank you! Just wondering: were you aware that the American Academy of Ophthalmology is located right there at Hyde and Beach in SF? The Academy actually has a Museum of Vision, chock full of fabulous vintage eye-related items. Just a thought if you delve into the world of vision again.

Kierstan Boyd
Director of Patient Education
American Academy of Ophthalmology
http://www.eyesmart.org

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