Central retinal vein occlusion, also known as CRVO, is a medical condition that occurs when the main vein that carries blood away from the retina becomes blocked. This condition causes sudden and severe vision loss and can even lead to blindness if left untreated. There are several synonyms used to describe CRVO, including central retinal vein thrombosis, central retinal vein obstruction, and central retinal venous insufficiency. These synonyms are often used interchangeably and refer to the same medical condition. It is essential to diagnose and treat CRVO promptly to prevent any further damage to the retina and restore normal vision.