I have yet to find a light that is manufactured as a booklight that I am happy with. I am currently using a headlight like
this but I don't wear it on my head. I reduced that straps down to their smallest setting and wrapped it around the cover on the opposite side from the reader. The angling of the head lets the light hit perfectly on the screen and the lowest setting is plenty bright enough. I still have to hold the cover like a book but I don't have to have completely hand-free reading to make me happy.
Just my $0.02.