Mammoth, a novel by John Varley https://en.wikipedia.org/wiki/Mammoth_(novel)

Highly recommend.

Does staring at two screens at the same time count double? At work as an iOS developer I look at two computer monitors, an iPad screen and a phone screen. When I watch TV at night I'll look at the TV and my phone. I'm sure I can get my count really high.

It might actually be better, as you keep changing focus.