iPad Air 2 — good for hours of viewing.
But eye strain is idiosyncratic.
One key to helping avoid it is the optometrist-ophthalmologist recommended 20-20-20 rule.
1. Every 20 minutes, take a break. Look at objects 20 feet (or more) away from you for at least 20 seconds.
Here are 3 others tips.
2. Remember to blink your eyes fairly regularly. That takes some effort to remember, but helps.
3. It's also smart to get up and walk around for a minute every 20-30 minutes. That's good for the body and general health, too.
4. Finally, take a complete break every hour or two and do some other activity that doesn't involve staring a screen or fixing your focus at a set distance — such as watching TV!
Doing those things will reduce or even eliminate eye strain and tired eyes for many, if not most, people!