I'm not a doctor, and I have no experience with that. However, I am guessing that you had blood vessels break - possibly capillaries break, and that is what caused your black eyes.  Maybe just stress.   Are you on any medications that thin your blood?  Maybe that helped trigger it.

Are you on a liquid diet now? or soft food diet?

Do you have a GI doctor on your speed dial now? In case this happens again?

I've never heard of your problem before. Thanks for sharing your experiences.