Standard Snellen 20'

For Use With 1258 Illuminated Eye Test Cabinet.
To Be Read from a 20' Distance.
Translucent plastic 14" x 9" eye charts.

The Snellen eye chart is the familiar chart with the big letter or symbol at the top and progressively smaller letters at the bottom of the chart down to 20/20 or better.

This is a chart for measuring visual acuity at a distance; how well you can see things that are far away.