Glaucoma is the second leading cause of blindness in the US, in which typically high pressure inside the eye damages the optic nerve, which carries the vision from the eye to the brain.  High blood pressure is a risk factor, and should be controlled medically as well as with diet (see next time’s column).  However, low blood pressure at night when we are sleeping flat can also damage the optic nerve; hence, I recommend to my glaucoma patients who take blood pressure medication that they consider taking it in the morning to avoid nocturnal hypotension.  Aerobic exercise and avoiding smoking are very helpful to glaucoma patients. Early removal of cataract can help glaucoma by lowering pressure inside the eye. Wearing a tie too tightly and sleep apnea (where snoring can cause collapse of the breathing passage) can make glaucoma worse as well. So I tell such patients to loosen their tie and see a sleep specialist for evaluation and treatment of possible sleep apnea (which could include weight loss, nasal strips, Pro-Vent, different pillows or beds, or assisted night ventilation with a CPAP machine).  Other recent findings of note are that early life UV exposure (snow or water sports), head-down positions during yoga, and heavy use of wind-blowing instruments (e.g., trumpet, oboe) or bad oral hygiene can increase damage to the optic nerve.