Three cases of unilateral visual loss caused by sinus lesion were encountered and we report three cases with literature review. Sinus inflammatory disease like sinusitis or mucocele is a common disease, but visual loss complicated by which is rare. It can be fatal and is known to have a poor prognosis. Appropriate and prompt management like intravenous antibiotics and surgical drainage must be done, when a patient is suspected of having visual loss by sinus problem. We report a case of unilateral visual loss caused by sinusitis, two cases by mucocele. The clinical courses and possible management are discussed.