Skylights and light wells (and prism tiles)
Bring more sunshine into your house: part 6
Even though they cannot offer the view to the outside that windows do, skylights and light-wells can bring light where there is no other way. Having just a skylight in a bedroom can be claustrophobic though, so don't overdo it. But in the case of the room too deep or too North, a good solution can be to bring some light from above. It can also help with regards to Alexander's idea, because it brings an additional direction of shade and our brains perceive objects better when they have more shade directions to calculate shapes from. A single light bulb from above is creepy, like in police questioning in movies. Portrait photographers use at least three light sources to bring out the best in the subject.
Of course, the reverse is also true: too many light sources erase all shadows, so the subject is indiscernible. A cool invention for natural light enhancement is the use of refraction to redirect light to the deep bits of a room. These magical helpers are called prism tiles and, as the name implies, are in the shape of a prism. So, like the Pink Floyd album cover, the light changes direction when it passes through them. Look it up, it's called anidolic lighting. And for those of your who are really into this sort of thing, here's an extract from an MIT course on daylight listing multiple "advanced fenestration technologies".