Definition that contains visual acuity
- snellen Dutch ophthalmologist who introduced the Snellen chart to study visual acuity (1834-1908)
- snellen chart display consisting of a printed card with letters and numbers in lines of decreasing size; used to test visual acuity
- 20/20 normal visual acuity, as measured by the ability to read charts at a distance of 20 feet
- snellen test a test of visual acuity using a Snellen chart
- hermann snellen Dutch ophthalmologist who introduced the Snellen chart to study visual acuity (1834-1908)
- twenty-twenty normal visual acuity, as measured by the ability to read charts at a distance of 20 feet