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 also measure the viewing distance from the chart to the patient’s eyes, also in millimetres.

Then just fill the form below with those values and you will receive an email instantly, with the calculation of the error of the AV values that your charts show.

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.