ShuriyuCSI, you're right. It's the makeup artist's choice, not the actor's. And the eyes are the one part that they want to highlight the most, onscreen. I worked in PR in the Hollywood area for 10 years, and I can tell you, literally everyone did something to highlight their eyes, first and foremost. Men wore mascara, subtle eye shadow, eye liner, etc. ALL the time. For some strange reason the makeup artist decided to really accentuate Gary's eyes in M2M, but it certainly wasn't unprecedented. Especially if the actor's eyes are light colored, blue or green, like Gary's. I don't really notice it too much on CSI NY, although I think the Grissom character on CSI/Vegas is always wearing some sort of eye accent, eye liner or mascara, I noticed it all the time, when I still watched that show. Once again, his eyes are blue, so the makeup artists are more likely to highlight them.