AIUI the problem is mostly the blue light. I can't imagine that becoming habituated to staring at a bright light is all that good either, but I don't know of any specific studies on that. It's also the kind of thing that only shows up statistically after twenty years, as a higher incidence of inability for the eye to accommodate to lower light levels etc. Nobody's going to look at a too-bright screen for a day or two and immediately notice a drastic difference.