A retinal artery occlusion (RAO) is a blockage in one or more of the arteries of your retina, a layer at the back of the eye where visual images are formed.
The blockage is caused by a clot or occlusion in an artery or a build-up of cholesterol in an artery. It is similar to a stroke. An occlusion causes damage to the retina due to lack of blood flow. In the short term, this loss of blood flow can cause swelling of the retina. If the blood flow remains poor, it can lead to death of the retina cells and loss of vision.
There are two types of retinal artery occlusion: