Why do giant pandas have dark circles?

When panda eyes have dark circles, they want to protect them.

Giant pandas have dark circles under their eyes to protect them. Giant pandas have long lived in bamboo forests, forests, mountains and other poor lighting environments. When they encounter strong light, their eyesight will be affected and they can't respond quickly to the current situation. The black hair beside the eyes can prevent the damage of strong light to the eyesight and help the giant panda find natural enemies or food.

Dark circles are caused by staying up late, mood swings, eye fatigue, aging and other reasons, which lead to slow blood flow in eye skin and blood vessels, resulting in stagnation.