Is it safe to use your iPad all day?

As safe as it is to stare at a computer monitor all day.

I Believe it's recommended (in general, not just for Apple products) to look up, focus your eyes elsewhere, close your eyes and let them rest, every so often. Just to help alleviate eye strain and dryness. Also best, like any computer monitor, to use them in well lit area so you don't add to the general eye strain by having a light screen in a dark room.

No... but I do it anyway.

Only if you don't get eye strain. You may want to see your opthamologist for an answer, not us users.

I have pretty much turned to my iPad Air 2 as my go to computing device at work for most of that I need to do. I use my iPad all day long. I used my iPad 3 all day long at work as well. I recently had my eyes examined and my eye glasses prescription had change ever so slightly. I attribute that more to the fact that I had not had an eye exam in over 10 years (shame on my, I know) and the fact that I am now approaching 63.

As Skydiver said, it's no different than staring at a computer monitor all day long. As long as you do the things that were suggested, you have nothing to worry about, as long as you don't have some underlying medical issue that you are not sharing, or your own eye doctor tells you otherwise.