It'll be interesting to see where the research around this stuff shakes out. There's research about nearsightedness[1] being linked to the amount of time spent with bright light, and some stronger research being done to dig into that further[2]. However there's also research showing that the blue light from LEDs could be damaging[3] (the fact that the human stand in is flies definitely means more research is needed). I wonder what a good balance will end up being.