I have constant pressure in center of forehead, behind eyes, and in my left jaw. all of sudden became really sensitive to light (fluorescent lights) & my eyes are extremely dry. no other symptoms no known allergies?

There is not enough detail here to make a diagnosis. There are many things that can cause headaches and dry eyes. You should make an appointment to see your primary care doctor soon. You should use over-the-counter pain relievers in the meantime, following the instructions on the package. Good luck.

I would start with a thorough examination by an ophthalmologist for diagnosis & treatment advice. You may then be possibly referred to a neurologist for evaluation. Appropriate testing will be ordered.