Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Glaucoma is a chronic and progressive eye disease that mainly affects individuals over the age of 60. It is the second leading cause of blindness globally after cataracts. Moreover, glaucoma is considered to be more harmful than cataracts because the blindness caused by this eye disease is irreversible and untreatable. Learn more about causes, symptoms and treatment of glaucoma in this book.