I like my big phone because a) I'm going blind in my old age, and b) the security requirements at the work keep my private life on my big phone, seperate from the network at the office.
Staring at a phone is not good for your eyes, due to the short distance. A small SE phone for critical/mobile tasks and iPad for reading is a practical combo.
We are still learning about eye health. The most profitable lenses for the optical industry are "progressive" lenses for 50+ and these should be avoided for computer use. See previous thread on alternatives:
It's a complex topic, depends on age, genetics, corrective lens or not, nature of your work and neuroplasticity. However, the eyecare industry agrees that max period for continuous closeup work (screen, paper, objects) is 20 minutes.
