Elevated epinephrine levels are associated with wide-open eyelids and large pupils, indicating increased energy and alertness.

“In fact, if you look at somebody and their eyelids are wide open, in large part, that's because of a lot of adrenaline in their system. If their pupils are really big and their eyes are really wide open, in general, that means they have a lot of epinephrine circulating there, whereas when we're tired and we're kind of hood-eyed and we're sort of sleepy, or our pupils are really small, in general, that's because levels of epinephrine and also dopamine, remember they work together, levels of epinephrine and dopamine tend to be lower.”