A snake may either bite the victim or may spit venom.
Venom that is spit into the eye can result in “snake venom ophthalmia” with:
(1) conjunctivitis
(2) corneal damage
(3) eyelid edema
(4) absorption of neurotoxins
If the person is bit then toxins may reach various parts of the visual axis. Some venomous snakes inject toxins that cause hemorrhage which can affect the eye or brain. Other venoms may include neurotoxins.
Rarely the fangs of the snake could penetrate the globe, injecting the venom directly into the vitreous humor.
Possible causes of blindness after snakebite include:
(1) cortical blindness (secondary to hypoxic ischemic encephalopathy)
(2) optic neuritis (from neurotoxins)
(3) retinitis (from neurotoxins)
(4) hemorrhage (retrobulbar, beneath the retina, into the posterior chamber)
