Thank you for the share. I think this article applies not only to spending time with steemit but also in using computer and electronic device displays.
If i can add to your article, you can also include plugins like the one i use in my chrome. You can install eyecare plugin. it normally open a new page every after 20 mins. This will distract you from staring your screen and un focusing your eyes from the screen. it will also remind you that you need to relax your eyes or exercise or do something.
I am not associated with the creators of eyecare buy i highly recommend the plugin. Here's the link.