Echoing what's been suggested so far. Assuming you've already got a good track for the eyes (you... ARE using tracking right?) and a roto in place, I'd start playing around with Sapphire Glow and Glint. The Sapphire suite doesn't get enough credit. If you move past the default settings you can really get some unique and lovely looking images.
Another idea to go along with Eake's suggestion of layering the image is maybe try offsetting the time by a frame or 2 to help with a cool trail effect. But yeah, even without Sapphire, duplicate, Add, levels, hue/sat, etc.
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