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What Does It Mean to Have 20/20 Vision?
The term "20/20 vision" refers to how sharp your eyes are when you look at a standard eye chart (Snellen chart) from a distance of 20 feet (or 6 meters)—depending on where you live. In the United ...
We evaluated the Runge card, a near-vision eye chart designed for ease of use, by testing agreement in visual acuity results between it and the Early Treatment Diabetic Retinopathy Study (ETDRS) ...
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