Eye, eye.

We had a model for our oil painting class but only had to stare at her eyes and ears.

I find eyes difficult when in a painting but much easier in isolation like this. The white of the eye is never white, is usually a different shade of grey on one side of the iris from the other due to catching the light at a different angle, is darker in a line under the shade of the eyelid and also darker in the corner of the eyes - so much to think about just for the whites of the eyes.

The iris is surrounded by a dark margin (more pronounced in young people). A "jellybean " of paler iris colour placed opposite the catchlight gives an impression of transparency and the catchlight is never white.

The lower lid is hardly painted at all.

This was a sketchier version.

The tear duct is a warm red.