Don't know if it's a punch or some medical surgery / implant.
Left eye, according to Horus mythology has a special power that the right one don't have. After Seth destroy the left eye of horus, Thot reconstructed it but a piece was missing, so he put some magic to complete it. Horus left eye then was called Oudjat (Protection). This new left eye was supposed to see the other world and favorise the access to other reality plans.
The left eye is supposed to be linked to the 3rd eye and to the pineal gland. (here's the link between left eye and another important symbol = pineal gland).
So could this black eye be a hematoma coming from some king of medical manipulation to expand their perception ?