Glaucoma is the condition in which Optic nerve undergoes progressive damage, looses its fibres, due to various reasons, commonest being high eye pressure.
Initially, it's the peripheral vision that drops out hence early stages are without symptoms( however, the angle closure variety, which occurs in 25 % of cases present with pain as the initial symptom). It occurs in 4-5% of people post 50 yrs of age and increases with age.
Family history, Past eye injury, Steroid usage, Diabetes, Hypertension, Uveitis, Impaired blood flow to the head region, Blood loss, Major surgeries, Sickness- increases the risk of developing glaucoma.
It can be managed with eye drops, lasers or surgery.