Maybe. Large studies published suggest that diabetes and glaucoma are not related. Then a few years later large studies suggest that diabetes and glaucoma are related. Easy thing to do is when you get your diabetes exam, ask your doctor if he sees glaucoma. Glaucoma is damage to the optic nerve. Half of the people with glaucoma have normal eye pressure. Most important risk factor is family history.
Not likely. Studies have been variable in answering this question. It is possible that uncontrolled diabetes affect the nerve due to its small blood vessel destruction as anywhere else in the body, but it is unlikely to be the primary cause of developing glaucoma. Because both diseases can progress without obvious symptoms, regular exams are important.