"technology to reproduce eye movements has been around since motion pictures were invented"

Sure, but like everything. It is when it is widespread that the impact changes. The technology was around, but now it could be on everyone's face, tracking everything you look at.

If this was added to TV's so every TV was tracking your eye-movements, and reporting that back to advertisers. There would be an outcry.

So this is just the slow nudging us in that direction.