I found this reference, maybe helpful.

"In the fight with Seth, Horus lost his left eye (and Seth his testicles - symbols of the causes of revolt, violence, sexual perversity and turbulence). This left Eye of Horus is the endangered & injured Eye, also called "the black eye" (his "empty Eye" torn out), associated with the cycle of the Moon (its destruction is associated with the New Moon, its restoration with the Full Moon). It was miraculously filled and completed by Thoth and then given back to Horus (as it is brought to Pharaoh) as a "full Eye" or "Eye of Thoth".