Well since you've had it 8 years and it hasn't lead to anything serious and you don't describe new symptoms its not likely anything that threatens your sight. If it is really troublesome, and it sounds like it is, I suggest you see a neuro-ophthalmologist. They specialize in things like that. There are some facial pain syndromes that might cause your symptoms. Neuroophthalmologists are usually in the department of ophthalmology at medical schools. If you live in USA you can go to www.geteyesmart.org and find a neuro-ophthalmologist near you.