I use PSE5, and I use the following steps to highlight eyes:
1. Save the file and work on a duplicate, as this can make irreversible changes. You want to have your original intact in case of disaster.
2. To first lighten the eyes a bit (if necessary) I use the dodge tool from the vertical menu. Its on the same command as the burn and sponge tools. Set the brush size to the fit the visible part of the eye. Change the exposure to between 17% and 25%. Run the brush across the eye a time or 2, or until you get the desired result. Note: the dodge tool is also good for lightening around the eye if need be.
3. Next sharpen using the sharpen tool on the vertical menu. It shares a spot with the blur and smudge tools, and is located just above the dodge and burn tools on the menu. Follow the same steps and settings with the sharpen tool as you did with the dodge tool.
For me, this produces sharp looking eyes which subtly draw attention. You may notice that I describe this as highlighting the eyes rather than popping them. I think that the current trend in eye-popping is producing results all too often reminiscent of vampire movies (lol, in some cases only a slight exageration!) and I prefer a more natural look.
I'm at work now (you can tell its the slow time of year in the accounting business!) and I'll have to try to remember to check on the sepia. I've only used it once or twice as an experiment, and can't recall how to get into it.