Looking at this painting "Portrait of a Young Man, 1507" by Albrecht Dürer at the Kunsthistorisches Museum I suddenly noticed the eyes.

The light in the eyes of the paintings, a tiny study of reflection, of light sources in the eyes of the subjects...

It made me think. And then it made me look at more images, and grab my camera!

Here is a closeup of the eye of the young man.

And an even closer view: You can see the mullioned windows in his eyes. Dürer was looking that closely at every detail.

Here is a photograph, From this high resolution portrait showing an eye...

There is so much I want to say about eyes...but this is a start.