1 Chronic glaucoma begins gradually over a period of months or years, usually in patients over the age of 40. There are no symptoms in the early stages, and the condition can be detected only by measurement of the intraocular pressure. Such an examination is recommended every three years for all persons over the age of 20. As the disease progresses, often the only symptom is a gradual loss of peripheral vision. It is a medical emergency that causes permanent blindness in two to five days if left untreated.
Surgery is usually necessary.
The Columbia Encyclopedia, Sixth Edition.