Some more technical details from this previous post:
So, why is this owl's eye green you ask?
Mammals have Bilirubin. It is responsible for the yellow color of healing bruises and the yellow discoloration in jaundice.
Avian species have Biliverdin (Latin for green bile), green tetrapyrrolic bile pigment, and is a product of heme catabolism. It is the pigment responsible for a greenish color sometimes seen in bruises.
The green indicates blood trauma that is healing his eye, and should be absorbed by the body and eventually disappear.










I think we could get Lucas to make another edit. What's one more at this point? ๐