Not all eye chart tests are the same, according to All About Vision. Different types of eye chart tests include the Snellen chart, the tumbling E chart and the Jaeger chart.
In the 1860s, Herman Snellen invented the Snellen chart, which typically shows 11 rows of capital letters, explains All About Vision. The top row usually consists solely of a large letter "E," and each row below contains different, progressively smaller letters. The tumbling E chart is similar in format to the Snellen chart, but it uses only the letter "E" in 90-degree rotations. The person reading the chart signals with his fingers instead of saying the letters. The Jaeger chart measures near vision instead of distance vision. The eye doctor can either place it at a specific reading distance or move it until the text becomes unreadable.