The Quran uses constant metaphors of blindness and deafness to imply unbelief. More severe cinchonism includes vomiting, diarrhea, abdominal pain, deafness, blindness, and disturbances in heart rhythms. Note that methanol is very toxic and causes blindness and death. This includes athletes with mobility disabilities, amputations, blindness, and cerebral palsy. Looking directly at the Sun causes phosphene visual artifacts and temporary partial blindness. Homozygous leopards are substantially more prone to congenital stationary night blindness. Less commonly seizures, blindness, or inflammation of the brain may occur. Symptoms and signs included&colon; inflammation of serous membranes, hemorrhages, apoplexy, convulsions, blindness and coma. There is no cure for color blindness. Suramin is a medication used to treat African sleeping sickness and river blindness. In subsequent decades, WHO largely eradicated polio, river blindness, and leprosy. For example, occlusion of central artery of retina results in blindness. The cause of his blindness is uncertain. It is a byproduct of inattentional blindness. His endeavors to save His people resulted in their "willful blindness" and His rejection.