Glaucoma is a condition that causes restriction of the visual field ie: Tunnel vision. No one knows the exact way in which this happens but we do know that the pressure inside the eye (the intraocular pressure) is an important contributory factor. It can run in families. Your optometrist will be able to arrange a ‘pressure check for you’. This is a condition that can only be picked up by a specialist as the patient is usually completely unaware of any problem.
The commonest form is chronic glaucoma
Treatment is usually with drops. Very occasionally surgery is needed.
Acute glaucoma is an emergency as it can cause very high pressure in the eye resulting in rapid visual loss. This requires admission to an eye ward. Symptoms include severe eye pain, loss of vision and nausea.