My 3 month old son eye doesn't seem to open as wide as the other eye. when he was first born he couldn't open it at all but now it's opened more?

Ptosis: can be congenital and can affect the development of vision. It is important to have your doctor examine your baby to determine if there is a neurologic or structural *(i.e.something blocking the eyelid) cause and then go on to an ophthalmologist to be sure the eyelid opens enough to allow normal vision. See http://www.drjordan.on.ca/pdfs/InSight_v6n4_Mar01.pdf