Henry, a 63-year-old diabetic male with a family history of blindness, went to the doctor with a complaint of severe pressure in his eyes. He also explained that for several months he has been having problems with his peripheral vision, such as blurriness and fading. During the last two weeks, his peripheral vision was almost totally lost. After an examination of his eyes by the ophthalmologist, it was found that this patient had thin corneal thickness, high intraocular pressure, and some loss of the visual field.