Hello Prolonged working on laptop/TV/mobile can cause computer vision syndrome. Computer vision syndrome is a condition resulting from focusing the eyes on a computer or other display device for, uninterrupted periods of time. Some symptoms of cvs include a. Headaches b blurred vision c. Neck pain d redness in the eyes e. Eye strain f dry eyes sometimes watery eyes these symptoms can be further aggravated by improper lighting conditions. Measures to reduce this include 1. Work under proper light. 2. Blink a lot. 3. Cold compresses 4. Use good lubricating eyedrop

Two reasons for headache while working on computer first refractive error & 2nd is dryness  ( computer vision syndrome),still I doubt your refraction has been done correctly after pupil dilation?,if not  do revisit experienced ophthmologist  for refraction after pupil dilation& use antiglare glass & for dryness you should try to have normal blinking while working on computer & also use lubricating eye drops 4-5 times regularly  (Refresh liquigel)& do read my old blog on Practo about precaution to be taken while working on computer, with regards