Snakebite is not necessarily snake envenomation. Of about 2,500 known species of snakes, only about 40 are regarded as being dangerous. A snake will not go out of its way to attack a person and even in defense, snakes bite humans usually to dissuade and not to kill.Early surgical excision of the bitten area is regarded as a most important aspect in the management of a poisonous snakebite, and because of the side effects of horse serum, cautious use of antivenin is advised only in cases of severe systemic poisoning.When a snake spits into the eyes, prompt treatment is indicated to prevent future blindness.