What are preventitive measures for glacoma?

Early detection. Glaucoma can silently steal your vision. Prevention of vision loss depends on early detection and treatment. The disease runs in families and routine exams are crucial so testing can detect the disease in its early stages. Control can be achieved with drop medication, laser, surgery or a combination! catching it early can avoid functional loss!
Regular checks. Unfortunately many people are unaware they have glaucoma until it has already caused damage, so you are right to ask about prevention. There is no way to prevent glaucoma so the best thing you can do is have your eye pressure checked by an eye doctor on a regular basis - especially if you have a strong family history.