Glaucoma Donate Fundraise Glaucoma is the leading cause of irreversible blindness in the world. Pressure is raised in the eye which damages the optic nerve and increasingly causes sight loss. New treatments, including improved eye drops and surgical techniques to reduce this pressure in the eye are being researched. Glaucoma is a term that describes a group of eye conditions that affect vision. Glaucoma often affects both eyes, usually in varying degrees. One eye may develop glaucoma quicker than the other. Glaucoma occurs when the drainage tubes (trabecular meshwork) within the eye become slightly blocked. This prevents eye fluid (aqueous humour) from draining properly. When the fluid cannot drain properly, pressure builds up. This is called intraocular pressure. This can damage the optic nerve (which connects the eye to the brain) and the nerve fibres from the retina (the light-sensitive nerve tissue that lines the back of the eye). In England, about 480,000 people have chronic open-angle glaucoma. Among white Europeans, about 1 in 50 people over 40 years of age and 1 in 10 people over 75 years of age have chronic open-angle glaucoma. You are at increased risk of developing open-angle glaucoma if you are of black-African or black-Caribbean origin. The other types of glaucoma, such as acute angle-closure glaucoma, are much less common. However, people of Asian origin are more at risk of getting this type of glaucoma compared with those from other ethnic groups. We urgently need to find new and more effective interventions to treat this leading cause of sight loss and blindness. Please donate to our glaucoma appeal now.