Compound eye of the Antarctic krill <a href="//commons.wikimedia.org/wiki/Euphausia_superba" class="mw-redirect" title="Euphausia superba">Euphausia superba</a>
Gerd Alberti and <a href="//commons.wikimedia.org/wiki/User:Uwe_kils" title="User:Uwe kils">Uwe Kils</a>
CC BY-SA 3.0
Photo