Hey guys, I have a question about the snellen chart. I have found two snellen charts online which can be printed on A4 size paper. But one of them says 10 feet chart and other says 2.8m/9feet measuring distance.

One of them mentions a "formula i.e -measure the height of the letter E (first line, 20/200) in millimeters. Then, divide the value of this measurement by 88. Finally, multiply it

by 6. The result shows the distance at which you must be placed, in meters. E.g. (42/88) x 6 = 2.8 m/9ft.

By using this formula both the charts printed on a4 size paper measures the same. The size of " big E" is same on both charts. If anyone has used home printed a4 charts please suggest how do you measure the distance.

Thanks