Can blood clot in vein cause vision lost?

Not likely : There is no connection between a leg vein clot and the circulation in your eye. Unless you have a defect in the wall of your heart , there should be no way that a leg clot can pass to your eye.

Yes. BRVO & CRVO.: Branch retinal vein occlusion (brvo) and central retinal vein occlusion (crvo) are due to clotting in these tiny retinal vessels. There are mild and severe vein obstructions leading to varying degrees of vision loss. In the last five years, several innovations in the treatment of these diseases has occurred. Early detection and treatment of the condition and it's underlying causes is key. Exam.