If you haven't yet seen a NEURO-ophthalmologist, I would recommend it. Not only does PD mess with vision (the National Parkinson's Foundation has a great publication on this) but also some of the medications we are on add insult to injury. For instance, it never occurred to me that my increasing light sensitivity had anything to do with either, until I happened to discontinue my dopamine agonist (Requip). The sensitivity disappeared instantly and entirely and hasn't returned since. Coincidence, maybe but I don't think so. Narrow angle glaucoma is also something to watch out for...