This Animal Has a Suit of Armor With Hundreds of Built-In Eyes
http://www.theatlantic.com/science/archive/2015/11/this-animal-has-armor-with-hundreds-of-eyes-and-lenses-made-of-rock/416523/
Because it contains eyes. Hundreds of eyes.
With lenses made from rock, that erode as the animals age and have to be continuously replaced.
Chitons are mollusks, related to snails, clams, and octopuses. Their oval bodies are covered by a hard shell consisting of eight overlapping plates, which makes them look a bit like a woodlouse with a skirt, or perhaps like the forehead of a Klingon. In many species, these plates are dotted with hundreds of tiny beads, each less than a tenth of a millimeter across. These are eyes. Each contains a lens, a light-sensitive retina, and a layer of black pigment.
There's also an article on WaPo with a close up image of the 'eyes'. (trypophobia warning)
https://www.washingtonpost.com/news/speaking-of-science/wp/2015/11/20/how-one-animal-covers-its-body-armor-in-stoney-eyes/
= new reply since forum marked as read
When I was in school, a "chiton" was this:
Because I was studying costume design. (an ancient Greek garment)
Here's the etymology from the Wiki page on the mollusk:
The English name "chiton" originates from the Latin word chitōn, which means "mollusc", and in turn is derived from the Greek word khitōn, meaning tunic (which also is the source of the word chitin). The Greek word khitōn can be traced to the Central Semitic word *kittan, which is from the Akkadian words kitû or kita’um, meaning flax or linen, and originally the Sumerian word gada or gida.
Just now looking at the wiki for chitons, I found out some chitons made use of a fibula. https://en.m.wikipedia.org/wiki/Fibula_(brooch)
Which shares its name with a bone in the lower leg so named because of it similar appearance.
