Carbon disulfide can damage the microvascular circulation and cause optic neuritis. "In severe poisonings, a central scotoma with an impaired red-green discrimination may be detected . . ." [Sullivan, p. 1209] Organophoshosphates and carbamates can cause miosis and temporary blurred vision. Symptoms of acute carbon monoxide poisoning can include dimmed vision. Other reported causes of visual impairment are lead poisoning, organic mercury and tin poisoning and chronic toluene abuse (sniffing). Direct contact with corrosive chemicals can cause acute visual impairment.