RESUMEN
To present a case of ocular toxocariasis in a young male subject from the north of Iran. A 29-year-old man presented to our clinic with history of decreased vision in his left eye from 10 days before. He had a history of similar symptoms 2 years ago. Visual acuity in the left eye was counting fingers at 2 meters but relative afferent pupillary defect was negative. The right eye was normal on examination but the left eye showed mild anterior chamber reaction together with +3 to +4 cell in the anterior vitreous. Funduscopy in left eye disclosed posterior vitreous organization in the superonasal area of the retina. Serologic test study for toxocariasis was strongly positive. Ocular toxocariasis is a rare but severe cause of unilateral visual loss in young healthy persons