It would look like this.

I still have to assume this is a joke (who would notice a blinking LED on your lower leg?) but the problem seems real enough. Hasn't this been largely addressed by Smart Pause, the technology that pauses YouTube videos when you look away? For this application you would want it set to be a bit less sensitive, but if you have a camera then it seems a simple matter of programming to pause playback if you go more than a minute or two without detecting (open) eyes.