Normally speaking, I think there is no direct causality between watching TV and developing glaucoma. Watching TV for a long time could cause eye strain. Because of long time staring, muscles providing the power of focusing would be sore and painful. Meanwhile the starring would reduce the frequency of blinking, which lead to deficient tear film lubricate eyes. So the eyes would be dry and red and the vision is blurry. Normally eye strain would cause headache, blurry vision, pain in shoulder. It might cause or worsen various eye problems. But eye strain won't cause very serious problems directly. As to glaucoma, it is the condition that pressure increased in eyes and killed the optic nerve endings. It is a serious eye disease which is the leading cause of blindness with no cure. The root of increased eye pressure is the imbalance of humor aquosus production and drainage. It can be caused by many factors, like diabetes and eye trauma. It is better to visit a doctor if you are suspicious of getting glaucoma.