strange pupillary dilation and constriction

I was noticing that my left eye's pupil has been dilating and constricting unusually. I am sitting in low light with a mirror and I can see my left pupil dilating and constricting over and over as if it can't figure out which one it really wants to be. I've been having problems with focusing on stuff while it's moving and with my equilibrium. Would this pupil symptom have anything to do with that? The right eye does it occasionally too, but it's not as noticable as the left eye. I've asked friends to look at it and they even think that is weird. I noticed that their eyes aren't doing it. I've shined a light in my eyes and they both constrict when a light is shown into them, although even with the light my left eye still looks like it's trying to dilate when its not suppose to. Any ideas as to why this would happen and if I should be concerned?

[John C Hagan III, MD, FACS, FAAO]

That quick up and down movement of the pupil is called "hippus" and is normal, especially in your people.

JCH III MD