Third Eye Question

[Mors_Indecepta]

I know there are already likely theories regarding white-eyed killers, but do we know anything about the significance of so many things in the entity's realm having 3 eyes?
Victor has a 3rd eye he likely didn't have in life.
Oni's mask has a 3rd eye, that you can even see in his portrait.
Maurice has a 3rd eye...but we know that's because the entity felt bad for blinding the horse, so it gave him a 3rd eye so it could see.
Many blighted skins also feature the growing of 3rd eyes, in killers that didn't previously have them, like Spirit.

Has anyone come across a lore reason for all these 3rd eyes?