Note: you may notice some slight differences in tinting. Because there's more contrast and detail in the irises, eye color may seem a little different than vanilla, but I haven't edited the tint map for eyes except to resize it, so it shouldn't be too dramatic.
Update: I've added a second version -- I'd been thinking about it anyway, and a comment prompted me to actually make it. The irises aren't quite as large as in the main version, if you want something in the middle.
Update 2: whoa, the first mod I've ever actually shared with other people and it's now in the hot files section? Dang. Maybe I'll actually polish up a couple of other things sitting around on my hard drive and get them ready for public consumption. Thank you, guys!