Brand: Graham-Field Category: Diagnostic Instruments Condition: New UPC: 2147483647 Non-reflective, matte finish with green and red color bars. 20' distance.Non-reflective, matte finish with green and red color bars. 20' distance. 22"; x 11";.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 - in other words, how well you can see things that are far away.