Maybe, if you're staring at a screen, it would influence you. But I never stare, I read... (and if I do start staring, it means I should put my book away and start sleeping
).
often, when I talk with people (collegues and such) about this, and I mention I turn down my backlight as far as it will go and change the colours to a dark gray on a black background, they often respond with: but how do you see it then? Which leads me to believe they haven't even tried it and are just repeating what somebody else said...
If I use that Mighty Bright, I get more light than if I use the backlight of my device...