Glaucoma is a condition where the pressure in the eye gets high enough to cause permanent and progressive vision loss. This can lead to complete blindness, if left undetected.
Just like the body, with its heart and blood vessels and blood, the eye has its own circulation. It produces a fluid called aqueous that bathes the inside part of the eye, providing oxygen, food, and electrolytes. It then exits through a fine netting into the venous system. If the eye produces too much aqueous or it gets blocked when exiting, the pressure in the eye will rise. When pressure rises it squeezes the blood vessels, slowing the flow of nutrients and oxygen to all parts of the eye. One can see that, if this condition were left unchecked, the eye would gradually die off. What makes regular glaucoma testing critical is that glaucoma is relatively symptomless in the early stages. Early detection is crucial.
Most cases of glaucoma can be treated with drops, taken regularly, to get the pressure down. Then, it is a matter of regular follow-ups with a field analyser and pressure tests to make sure the conditon is under control.