If I cannot use my eyes because they are too tired, they are “killed” for the day, in my book. As the other comment says, your own source makes the opposite point that the one you were probably trying to make.
We're clearly using different interpretations of the word "killed".
I have no memory of my eyes being "killed for the day" so I was asking for evidence that maybe I am accumulating eye damage that will eventually catch up on me.
No matter what it is, in COVID times when everyone uses the screen 8h+ / day we should have some better screen tech, which is at least as good as a book. It can't be that this occupational hazard should be accpeted like it is right now.
Other professions like medical radiology imaging are more forward thinking in this: http://europepmc.org/article/PMC/5449879