Cannabis can affect the eyes. There's no doubt about that. But from what I've read, uneven pupil size happens more frequently with other street drugs that we can't talk about here. It also can be the side effect of some prescription drugs.

It can also be a perfectly common feature in eyes. About 1 in 5 people don't have perfectly evenly matching pupils.

From what I'm reading in my husband's Lange/Clinical Neurology, it can also be something that happens as a result of congenital syndromes or of certain syndromes affecting the oculosympathetic nerve.

If the pupils are markedly different, particularly in the context of response to light and/or loss of consciousness, there's something neurologically or vascularly serious going on. This book also says thyroid trouble and glaucoma can cause the symptom, too.

My intuition makes me suspect that this kid's eyes have always been that way--or he's been doing a rather interesting combination of recreational substances. He's kinda young to be having an aneurysm, tumor, or glaucoma.

Image Reaper, did anyone ever figure out what was up with your eye?