It is said that eyes have "life". They do literally, of course, as part of a living being, but what is meant is that as part of a person's countenance they are expressive.

Well, what is actually meant, I guess, since the eye itself only has pupil dilation and direction to work with, is that the surrounding musculature is expressive.

Phrases such as "lit up" are metaphorical and somewhat romanticised descriptions of sudden displays of enthusiasm, or whatever.

I don't think I've ever considered for one moment taking the metaphor literally; why would I?


On the other hand, one of the reasons firelight and candlelight are considered so romantic is the glorious effect when they glint in one's beloved's eye. IMHO, at least.

Furthermore, the eyes and the surrounding region of musculature are one of the areas the brain appears to key off most strongly when recognising somebody: TV documentaries and the like often just obscure the eye region when they want to display a picture of somebody without it being too easily identifiable. I guess that makes it more likely for us to ascribe changes of expression to a person's eyes.