Damage to the optic nerve, often due to high eye pressure. You usually notice it late.

The fluid in the eye does not drain well, so pressure rises and the optic nerve fibres are slowly lost. The risk increases with age, family history, strong short-sightedness and certain ethnic backgrounds. In the acute form the drainage angle suddenly closes.
Contact your GP or the out-of-hours GP service (huisartsenpost) straight away if you have:
This page is a short summary and does not replace a consultation. Want to know how the eye works? See The eye.