What do you mean by "light bright"? Are you saying that the backlight is too much? Or are you saying that the pixel density is too low, thus resulting in a view that looks like an old Lite-Brite
What I find works for LCD is to get as high of a pixel density as you can, at least 150ppi (most computer monitors are 100ppi or less, though a 1920x1080 15.6" laptop screen is almost usable at ~140ppi). This means you should probably look at smaller devices like the Nook Color (the iPad is 132ppi, so not good enough). Next, reduce the brigthness level of the screen. Finally, use a reader that has a "night" or white-on-black mode. It's much easier on your eyes to read white text on a black background than it is to read black text on a white background.