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.
The program will indicate the VA that is actually being measured with that letter size and viewing distance.