Can a corn snake see everything? It seems that my corn snake acts like he can actually see me. If I move somewhere in the room he will look right at the direction I am at. I mean snakes like to do things in the night but if corn snakes or any snake can't see then how are they able to kill their prey?
Eyesight in corns, in common with that of many snakes, is considerably less acute than in humans. There are two primary aspects to this:
- The snake's eyes do not have lids like ours, so do not get cleaned other than when the snake sheds its skin (the shed skin will include eye caps). This means that they have to be hardier and less prone to damage from abrasion in order to remain useful for several weeks, even when subjected to potentially harsh treatment when burrowing. This contrasts with our eyes, which are soft, and which get cleaned several times a minute, and which have therefore been able to evolve to give sharper, clearer sight.
- The light sensitivity in humans comes from the combination of rods and cones, which gives us the ability to discern the range we call "visible light". Wikipedia's article on colour vision gives greater detail on this, but it is essentially the cones which give us colour vision, rods being more useful in low light. Snakes, on the other hand, have sensitivity to a different range: this article on Serpent Sight, published in the Journal of Neuroscience shows how they are sensitive to ultraviolet light as well as to "mid-range" visible light. They do not have sensitivity across the whole spectrum of visible (to human) light.
Some snakes, particularly vipers and boids/pythons, have heat pits which are sensitive to infra-red, but corns do not have this. Corn snakes are, however, particularly sensitive to scent, so you might be observing behaviour in your snake which is a combination of initial interest on account of your scent and then "tracking" you by watching where the movement is occurring.