Using a simple “screen” mode (photoshop) layer is the a very easy way to help bring to life the face and eyes. In this photo I duplicated the photo layer and changed its mode to screen. I then (option clicked) on add layer mask which adds a completely black mask. Then using a white brush at 0% hardness while the layer mask is highlighted I filed in the eyes and parts of the face that were to dark allowing them to be shown in the screen layer. Next you can play with the feather and opacity amount on this layer which will be different for every photo.