Kyle macdonald (if you are getting into interactive stuff then it is a name you should know) has made this addon for openframeworks https://github.com/kylemcdonald/ofxCv, it has been ported to a variety of platforms including vvvv, and I think processing (it was a WIP last time I checked but active) but not to Isadora, it has some good and basic face fature tracking. For more detailed eye position information you can try using this library, again it is for openframeworks https://github.com/kylemcdonald/ofxFaceTracker it has the eye tracking stuff ready to go as long as you can get the user into the right situation (as with all of these solutions- ie have their eyes clearly visible from a god angle in the camera) ,the eyewriter project linked above is kind of dead and you will go crazy trying to get it going as it relied on a lot of custom code that you will not find easily.
Isadora will be able to play back content (it is great for movies), but no other software will play your maya files, mayas rendering pipeline is unique and if you wanted this to be interactive you need to re-create it in an interactive environment. Typically for this kind of application people use unity or unreal game engines and then remote the system with OSC, or make the visuals using shaders and pure opengl/glsl and run them inside OF, or processing. As yet Isadora lacks the capability to support this as well as lacking a community of custom actor designers and a simple system for integrating external libraries into custom actors.
