I used to get a sense of eye strain and occasionally a bad headache each time I stare at my surface 3 screen for just a few minutes. Yet I'm not quite sure whether this was caused by the so called PWM dimming technology as is used in Pro3. Some said there is no PWM on surface3, but a review at Microsoft Surface 3 Tablet/Convertible Review suggests that the display definitely uses the PWM, which was noticed by their tools in the lowest 2-3 brightness levels. Do you guys have the same problem? What causes the eye strain and the headache?