There's a term for that: “Hippus” or pupillary athetosis. Or, possibly, as pointed out by earlier posters, if you are shining a light in your eye to look at your pupil in the mirror, depending on the angle of the light source, more or less light m... read more
In addition to stress, eye strain from constant computer use or from wearing eyeglasses with an outdated prescription can cause pupils to pulsate throughout the day. Taking frequent breaks from staring at computer and mobile phone screens or tablet devices can help prevent pupils from pulsating as often, according to Shape Magazine. read more
Causes of a pulsating eye include eye infections or irritation, lack of sleep and fatigue and stress, Healthline states. In most cases, eyelid pulsation does not indicate that there is a serious underlying disorder. read more