Okay, I did some experiments and here's a render of the results. It still needs some work, but I wanted to show how it looks so far. I think it all depends on the shape of the "wetness band" (don't know how to call it), its position, and the light setup. I made the shape in trueSpace. It's a half sphere, the top vertices of which are shaped so that they follow the contour of the lower eyelids. The top of the half sphere was beveled so that there would be a somewhat round edge there to catch the light.