How do snail’s eyes work


How do snail’s eyes work

In: Biology

Not all snails can see. Visionless snails move around using their tentacles and a good sense of smell.
Some snails can only see differences between light and dark, while others can clearly make out prey and other targets. Every snail species is different, but carnivorous snails generally have better vision than herbivorous snails because they need that vision to hunt. Snails also have different eye types – some have eyes that work like pinhole cameras while others have vesicular eyes with functionality more closely matching the eyes of a human.

It is very complicated to explain but I will try my best. So basically snails are evolved from clams and mussels which are still mollusks, but they dont have any eyes. These evolved into limpets which are marine mollusks(with eyes) that never leave the rock they were born on.They have cup-shaped eyes. Snails evolved from these.

Snails acquired a deeper eye cup than limpets and the visual opening, or the eyeball got smaller. The smaller the eye gives more sharpness to the picture the snail is seeing but since there was only a small amount of light falling through the visual opening, the image was dark.

So, because of this snails acquired refractory fluid, which broke the light into rays, making the picture brighter.

Finally, a layer of skin cells grew over the visual opening, the outer skin grew over the opening, and the refractive fluid turned into a bubble.