system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we get car sick looking at our phones or reading a book?

This has always floated around in my head. I'm usually always doing something so I'm always in the car. I often use my phone, so why done get car sick?
gpt
Basically, it's down to a mismatch between what your eyes are seeing and your body is feeling. 

Your body senses that you are moving forwards. But your eyes are focused on a book, so they don't report that you are moving. When this reaches your brain, it recognizes that there's a mismatch there. One sense says you're moving, and the other says you aren't. As far as it's concerned, it's not possible for you to be stationary and moving at the same time, so you have to be hallucinating.

It then makes you nauseous, because it thinks you've eaten something to make you hallucinate, and wants to make sure that you throw it up if possible.