1. In theory anyways, any distance time is useful. Relax ciliary, more distance challenge.
Can be a fun ongoing project to find random things that may be fun to do not related to screens, even during less well lit times. Indoor rock climbing gym, rebuilding an old Vespa, I myself have spent quite a bit of time musing on how to not just reach for the scrolly thing.
2. Differentials just for screen use. Otherwise however you see fit! 🙂