Central retinal artery occlusion is a rare event and the site of obstruction is not usually visible on clinical examination; therefore, the precise cause is often speculative. It is currently believed that the majority of central retinal artery obstruction is caused by thrombus formation. Atherosclerosis is implicated as the contributory event in most cases, although congenital anomaly of the central retinal artery, systemic coagulopathies, inflammation, or low flow states from more proximal arterial disease may also be present and make certain individuals more susceptible. Further indirect evidence against emboli as a frequent cause of central retinal artery obstruction is the 40% or less probability of finding a definitive embolic source on systemic evaluation and the small incidence of confirmed associated ipsilateral cerebral emboli in affected patients [1,2]. There are many reports that find an association between smoking and cardiovascular disease and the incidence of retinal emboli [3,4].