This is blockage of an artery within the retina. This causes the affected retina to lose it’s blood supply and therefore causing loss of vision. The severity of the loss depends whether it is the main artery ie the central retinal artery or a smaller artery that is affected. Unfortunately there are no effective treatments for a main arterial occlusion.
Very occasionally the blockage is only temporary. This causes transient loss of vision, like a curtain coming across the vision – we call this ‘amaurosis fugax’
This condition could be a precursor of more life threatening conditions such as heart attack and stroke. The most common causative factors are smoking , high blood pressure and raised cholesterol.