There is already "work" being done to detect the user's eye focus. If the user looks away from the ad, the ad pauses, until the user refocuses on their garbage. Granted, for now, it's 20 mins of ads for free tickets, and it makes sense. We also know humans don't understand the word, "enough" when it comes to profits.

https://futurism.com/moviepass-eye-tracking-ads