We have a new version of the eye tracker (2.0) that we are working on which is glasses-less -- should be out soon.
http://collab.eyewriter.org/?p=102 http://collab.eyewriter.org/?p=123
here's it in action (eye is chasing the cursor):
http://visiblevisible.org/deliver/tempt/EyeRec0602_1_Half.mo...
everything is open source / on instructables:
http://github.com/eyewriter