Glaucoma is a condition that results in damage to the optic nerve which connects the eye to the brain. This causes gradual and permanent vision loss. It is the world's leading cause of blindness.
Symptoms of glaucoma can often be hard to notice as the condition can develop very slowly. However, some types of glaucoma can happen very suddenly.
Glaucoma is most often linked to an increase in pressure in the eye. This damages the optic nerve and retina nerves, causing permanent sight loss. Older people are at increased risk of developing glaucoma. Early treatment is essential and can slow its progress or stop it getting worse.
There are four types of glaucoma. The symptoms that you experience will often depend on the type of glaucoma that you have. Chronic open-angle glaucoma is generally the most common form of the condition and has very few noticeable symptoms because it develops slowly. With this form of glaucoma, your side vision (known as your peripheral vision) is affected first and then your central vision.
Acute angle-closure glaucoma happens very rapidly and has very severe symptoms. These include severe pain, headaches, redness in your eyes, seeing halos around lights and losing your vision very suddenly.
Secondary glaucoma is often caused by other conditions like uveitis, and so it can be easy to confuse symptoms. Developmental glaucoma is a rare condition that affects babies.