Glaucoma is slow progressive form of blindness, taking many years to develop. It is thought that you need to lose about 30% of the axons of the optic nerve before it starts to affect your vision. This loss is irreversible. Hence, in the early stages of the disease, the patient may have no problems with their vision. In the intermediate to late stages, the peripheral / side vision is affected as you lose more axons. In advanced stages, the central / reading vision is affected. More often than not, the disease is more advanced in one eye than the other. The present mainly focused on etiology, epidemiology, classification, risk factors, diagnosis and current treatment of Glaucoma