Regarding screen use vs reading a book, I've read some discussions here regarding this, particularly on 'reflected' vs 'transmitted' light. Some HNers say there is no difference because light is still light arguing this distinction is pseudoscience, but I'm left unconvinced. An argument for the distinction I've heard is that 'transmitted' (or perhaps, better, 'emitted') light gives a false image that doesn't allow the eyes to focus well. Does anyone know (of a good article that explains) the science behind this?