When I train very seriously, my eyes change colors! Well, maybe not my eyes, but the area around my eyes becomes darkly colored - as if I was wearing eye shadow or something.

It happens especially when I train with a focused intent to destroy and kill with effeciency. It just looks dark around my eyes.

Its very wierd. Maybe its some nifty human defense I've never heard of or something. Armadillos have shells and claws, maybe humans eye sockets darken when they get dead serious.

Its not the lighting, because I've inspected it up close under the same lighting and posture before and after training. Its the skin itself that changes tint to a bluish black.

Its kind of wierd, so I was wondering in anyone else has noticed anything like that?
Or has heard of anything?
What does that mean?
This is a new one on me.