Visual Acuidity Chart

The standard logarithmic visual acuity chart, also known as the modified Snellen chart or LogMAR (Logarithm of the Minimum Angle of Resolution) chart.

Primary Use: This chart is used to assess a person’s visual acuity, i.e., the sharpness of their vision.

Structure: It displays “E” letters of various sizes and orientations (up, down, left, or right) across several lines. The letters decrease in size as you move down the chart.

Formulas: The chart includes formulas for calculating visual acuity (V) and design distance (D), as well as the LogMAR (L) value, which is a logarithmic measure of visual acuity.

Test Distance: A design distance of 2.5 meters is specified for the test.

Additional Tests: At the bottom of the table, there are circles with colored numbers, suggesting an integrated color vision test (Ishihara type) to detect potential deficits.