1) Chronic Glaucoma:
It is a slow progressive disease process and causes visual loss so quietly that the patient is unaware till the final stage of the disease. There is a rise in the pressure of the eye, higher than what the eye can tolerate, for a long period of time due to which nerve damage occurs resulting in loss of sight.
2) Acute Glaucoma:
Its onset is quite sudden. The patient develops sudden blurring of vision with severe pain around the eye. Every attack of acute glaucoma, mild or severe, leaves behind some residual damage. At times the attack may be so severe, that if not relieved promptly, blindness can result in a matter of days.
3) Congenital Glaucoma:
This occurs in new born infants. The child's eye appears cloudy and becomes abnormally large in size. If not diagnosed and treated, it leads to irreversible blindness at an early stage.
4) Secondary Glaucoma:
This type of glaucoma occurs as a side effect of some other disease process in the eye, eg, bleeding, inflammation, tumour, hyper-mature cataract, etc.