Special Eye Charts

There are some special eye charts that are used for various other purposes than the Snellen chart is!

The first one of these special eye charts is the astigmatic mirror that is used to diagnose and reduce astigmatism. Here is the chart (credit: www.i-see.org):



If an astigmatic looks at the lines near the center, some of the lines look darker in some directions than others.

A typical astigmatic will see the lines near the horizontal clearer and darker than the vertical ones. Horizontal lines may look spaced wider than the vertical ones, too!

Also the inner circle may not look quite round in shape.