You know the conch, it is that large marine mollusc with a spiral shell. Maybe you never spared a thought about it, but these sea creatures have two round eyes on the end of stalks that extend when they want to have a look around. Handy for peering above and even behind their own shell, as any nosy neighbour, conch eyes can be retracted back into the shell in an instant if they don’t like what they see.

More information:

gizmodo.com/holy-shit-conch-eyes