The causes of non-arteritic retinal artery occlusions rarely originate from the eye itself but are mostly the result of thrombo-embolic events which often develop due to atherosclerotic vascular changes, which in turn are often a consequence of internal diseases. In this article the most important internal medical examinations to identify related risk conditions are highlighted, which ensure that appropriate therapy can be initiated to reduce further possible vascular events. Additionally, a critical assessment is made concerning the implementation of thrombophilia diagnostics.