A protractor is used to draw and measure angles. An angle is the amount of turn between two lines. Angles are measured in degrees with the symbol °. Angles can be labelled with 3 letters (eg DEF) to ...

Acute angle-closure glaucoma is a rare but serious type of glaucoma. This condition occurs when drainage canals in the eye become blocked. If a person does not get treatment, acute angle-closure ...

Glaucoma is when the optic nerve in the eye becomes damaged. The different stages of narrow angle glaucoma relate to the extent of the damage to the optic nerve and the level of pressure in the eye.