Hi!!!
Andrija I was about to use also de Blink Detection but i reached the same conclusion that Alex and user can get tired.
I have still to make some experiments but my idea is to use the head rotation and detect a key position of the head to trigger events.
If you want to interact by blink detection maybe you will want to combine Tobii with Neurosky whose SDK has a blink detection (or that is what my boss told me).