Calibration for subject's viewing distance

 

For Symbol Acuity and Crowding the viewing distance must be calibrated based on the size of the image on your screen, however for all tests, it would be best if the viewing distance was correct. Use the resources below to calculate the correct viewing distance

Viewing distance for Symbol Acuity and all tests EXCEPT Crowding

Times the length you have measured by 10 to get the viewing distance for Symbol Acuity and all tests EXCEPT Crowding

Length of line on your screen (cm)	Correct viewing distance (cm)
3	40
3.5	45
5	65
10	130

 

Viewing distance for crowding

Length of line on your screen (cm)	Correct viewing distance (cm)
3	180
3.5	210
5	300
10	600