Snellen Chart

In order for a certain degree of test accuracy it is important to follow this procedure:

Letter height and distance in reality:

• Letter A: 88mm in height
• Standing Distance from Image: 6 meters

To work out the distance you are required to stand back from your monitor you will need to measure the letter A at the top of the image in millimeters and work out this equation on a calculator:

Standing Distance in Meters = 6 x (Height of Letter A / 88)

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