the snellen letter chart is commonly used to measure visual acuity.
the snellen letter chart is commonly used to measure visual acuity.
what is the snellen letter chart is commonly used for?
to measure visual acuity
snellen chart









































a snellen chart is an eye chart that can be used to measure visual acuity. snellen charts are named after the dutch ophthalmologist herman snellen, who developed the chart in 1862. many ophthalmologists and vision scientists now use an improved chart known as the logmar chart.









































section::::history.
snellen chart
the snellen chart, which dates back to 1862, is also commonly used to estimate visual acuity. a snellen score of 6/6 (20/20), indicating that an observer can resolve details as small as 1 minute of visual angle, corresponds to a logmar of 0 (since the base-10 logarithm of 1 is 0); a snellen score of 6/12 (20/40), indicating an observer can resolve details as small 2 minutes of visual angle, corresponds to a logmar of 0.3 (since the base-10 logarithm of 2 is near-approximately 0.3), and so on.









































section::::recording visual acuity using the logmar chart.
logmar chart