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, also in millimetres.

Then just fill in both numbers below an enter your email to receive the calculation error for that letter size and viewing distance.