User blog comment:G0LD3NF1RE/Skyrim Dawnguard DLC/@comment-86.180.170.16-20120503162218/@comment-30303790-20120503164102

The whole vampire thing comes from a series of things found just before Bethesda gave us this announcement. Among the items was a set of new feeding animations for vampires, and without that, vampire eyes might probably wouldn't be guessed as frequently.