corneal facet

cor·ne·al fac·et

a corneal depression following loss of stroma.
Farlex Partner Medical Dictionary © Farlex 2012

corneal facet 

1. Small flattened depression on the outer surface of the cornea, due to a healed ulcer which has failed to fill with tissue.
2. The corneal element in the ommatidium of the compound eye. See compound eye; corneal ulcer.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
References in periodicals archive ?
Because photon catch is proportional to the cross-sectional area of ommatidial corneal facets, a single Limulus ommatidium (0.029 m[[Mu].sup.2]) should catch [approximately]1.8 times more photons than a Tachypleus ommatidium (0.016 m[[Mu].sup.2]).