The invention relates to a method, system and computer readable medium for determining a strabismus angle of the eyes of an individual by: positioning the individual with his or her eyes in front of an eye tracker device and in front of a screen at a viewing distance； displaying a small image element on the screen； measuring a position and line of sight of the eyes of the individual with the eye tracker device while the individual is focussing on the small image element； forwarding the measured position and line of sight of the eyes from the eye tracker device to a computer system； and, calculating the strabismus angle between the eyes by calculating the difference in line of sight of the left and right eyes of the individual.
