ocularium

Etymology
.

Noun

 * 1) A slit in a helmet through which the wearer could see.
 * 2) An elevated mound or "turret", found in some arachnids and other creatures, which contains simple eyes (ocelli).
 * 1) An elevated mound or "turret", found in some arachnids and other creatures, which contains simple eyes (ocelli).

Alternative forms

 * occularium