Glaucoma is a disorder of the eye where the vision of the eye deteriorates due to optic nerve damage. It is the leading cause of blindness after cataracts, but it is not noticed as much, hence it is regarded as the "silent killer" of vision. There are various types of glaucoma, and misdiagnosis is common.

Glaucoma, if left untreated, usually leads to blindness. In most types of glaucoma it is not possible for the patient to notice the problem until damage is already well in progress. So early detection of glaucoma is important to preserve vision.

Glaucoma is often associated with an increased pressure inside the eyeball, but this is not always the case. This makes it hard to diagnose correctly by a non-specialist. About 90% of people diagnosed as having glaucoma only on the basis of measuring the eye pressure do not actually have glaucoma. Conversely, about a third of the people who do have glaucoma cannot be detected just by measuring the pressure. Glaucoma diagnosis and treatment are best done by a glaucoma specialist like myself rather than by general ophthalmologists.

Most types of glaucomas cannot be diagnosed in one session by an ophthalmologist, especially in the early stages. A glaucoma specialist needs to run several tests before making a diagnosis. Only after these tests have been done can a glaucoma specialist use their expertise to decide the optimum treatment.

The Royal College of Ophthalmologists has a good patient information leaflet on glaucoma, written in plain english. Do bear in mind, though, that it is aimed at people in the UK.