Verify the Calibration of your Visual Acuity Charts

To check if your visual acuity charts are correctly calibrated, please measure the height of a 6/60 S(m) letter (corresponding to 0.10 Dec, 20/200 S(ft) or 1.00 logMAR). You must measure the viewing distance from the chart to the patient’s eye.

Then fill both values (in millimetres) in the form below, as well as your email, and you will receive an email instantly, with the calculated error in the VA values displayed by your charts for the stated viewing distance.

If you wish, you can repeat the process with other VA sizes (for example: 6/12 S(m) 20/40 S(ft), just to be sure.