It’s All About the Eyes
If your subject’s eyes are dull and lifeless, your image will project that too! Before you take your photograph, check that the model’s eyes have catch lights in them.
How to Make Those Eyes POP in Photoshop CS
Step Four: We need to be really careful that people can’t tell that we have lightened the eyes. So select the highlights range (you find this above your image). Then set the exposure to 10%. This will make sure we are just lightening the highlights gradually.
Step Five: Brush over the whites of the eyes. BUT be very carefully that they do not look too white! Zoom out to check. I often dodge the catch light in the eye also if it is very light.
Step Six: Darken the pupils. Select the burn tool (it will swap over with the dodge tool if you hold down on it.)
Here is a before (left) and after (right) example.
Darkening the pupils and eyelashes definitely gives the eyes more impact. I sometimes very slightly darken the nostrils as well, to give the image more depth.
I hope this tutorial has been of help to you,