Glaucoma is a condition that damages the optic nerve in the eye. This nerve is essential for vision as it connects the eye to the brain.

The symptoms of glaucoma vary with the stage. However, the following are some of the symptoms:
- Patchy blind spots in the eyes
- Pain in the eyes
- Headache
- Blurring of vision
- Vomiting and nausea
- Redness of the eyes
- Watering of eyes

The increased pressure due to excess fluid in the eye causes glaucoma. This damages the optic nerve if left untreated. Normally, the fluid is drained from the eye continuously, maintaining the pressure in the eye. The excess production or improper drainage of this fluid causes glaucoma. Genetic factors and high blood pressure too can lead to glaucoma.

Following factors increase the risk of developing glaucoma:
- Age over 60 years
- Family history of glaucoma
- Abnormally thin centre of the cornea (a layer of the eyes)
- Extremely nearsighted or farsighted
- High internal pressure in the eyes
- Diseases like heart problems, diabetes, sickle cell anemia and high blood pressure
- Corticosteroid medications
- Eye injury or eye surgery

The following tests are performed for the diagnosis of glaucoma:
- Visual acuity test to check how far you can see clearly
- Visual field test to check your side vision
- Dilated eye exam in which an eye drop is used to dilate (widen) your pupils and eyes are examined with a magnifying glass
- Tonometry to measure the pressure in the eyes
- Pachymetry to measure the thickness of the cornea