Originally Posted by tomsem
I can understand why you might prefer to turn it all the way up (makes it easier for eyes to focus when there's more light coming into your eyes, causing your irises to contract—pinhole effect etc.) but at that point it is probably no different physiologically than reading a backlit screen in terms of messing up sleep cycles.
That is a major concern. Basically, blue and white LEDs must be avoided. I really do not know what kind of light to use with my reader to avoid messing with my sleep cycles.