A system for determining a spherical power of the eyes of the subject based on the measured refractive error associated with the red reflex image is provided. The system (i) predicts a position of a plurality of facial landmarks on the facial image of the subject, (ii) extracts the eyes from the facial image based on the facial landmarks, (iii) determines a position of the eyelid, (iv) determines a red reflex in the iris of the eye, (v) locates the red reflex with a reddish hue and a crescent in the iris for measuring the refractive error, (vi) generates a mask of the crescent by thresholding the red reflex image, (vii) determines a width of anti-crescent in the red reflex image, and (viii) determines a spherical power using the width of the anti-crescent, eccentricity and working distance of the image capturing device and a diameter of the pupil.
