At the bottom of the screen, there is a shadowing and very faint headlight effect from the LEDs. This is mostly hidden if the light control strip is set to black. I find that strip more obtrusive than the shadowing, so I keep my light control set to clear. The shadows don't really bother me, and I mainly read in the dark with the Glo light on its lowest setting (and that's still a bit bright!) The rest of the screen is a sort of creamy-white, and is evenly lit with no splotches or shadowing above the light control strip.
I haven't found the need to put the light on during the day to read, so no problems with the shadow strip during the day.