How to see with eyes made of rock
A chiton studs its armor with mineral lenses that aid sight but can weaken shell
MOLLUSK MULTITASKING Armored plates of the backs of these West Indian fuzzy chitons not only protect the soft mollusk flesh underneath but also see rough images thanks to hundreds of small, embedded eyes.
Sönke Johnsen/Duke University
Certain species of the crawling lumps of mollusk called chitons polka-dot their armor-plated backs with hundreds of tiny black eyes.