[NSILMike]

Charles just reminded me (by mentioning blue shade) of something that might help. When I am reading on my LCD tablet at night, I use an Android app called "twilight." It is free from the google store, and the purpose is to reduce the natural blue light emitted from LCD screens, which (at night or near bed time) suppresses the bodies natural melatonin. In other words, too much blue light at or near bed time will make it difficult to sleep. There are at least a couple of other similar options there, too.