Retinal Vein Occlusions
The retina is the layer of tissue that lines the inside of your eye that senses light. It is nourished by blood vessels that enter your eye. When there is a blockage of the veins, a retinal vein occlusion (RVO) occurs. If the major vein is blocked, it is called a central retinal vein occlusion (CRVO). If it is one of the smaller branches of the central vein, it is called a branch retinal vein occlusion (BRVO). The blockage can cause part of the retina to be damaged. This damage can lead to vision loss.
The symptoms of an RVO are painless blurring of the vision. This can be part or all of your vision, and generally occurs in only one eye. The vision loss occurs suddenly or over a few hours.