So what can we do? Well let me show another picture, the same view taken the same time of day, but the sun has been obscured by some heavy clouds:
So here is something that you can do: hanging light, gauzy white curtains in front of a southern window will scatter the light in all directions, creating a very even, very pleasant light all over the room (if the curtains are too lacy, i.e. with a bunch of small holes, this will not work as well). To illustrate, here is the same view again, same time of day, not a cloud between the sun and my window, but with an ordinary white bed sheet tacked up in front of the window:
(I think that is Cleo's ear right there ^ )Even the ceiling is pretty well lit here. True, there is still a fair amount of glare by the window itself, but everything else in the room is beautifully even. This is ideal lighting for most tasks.
The white curtain is a very low tech, very cheap fix for a south facing window. Closed, it provides privacy and diffuse light. On a heavily overcast or rainy day you may want to open it, as the curtain does reduce the total amount of light getting in (some is reflected back out the window again).
There are other, more permanent solutions as well (like using frosted glass) but they are mostly more expensive, and as above, not up to an individual tenant or worker. Also, frosted glass makes a view from the window impossible, while curtains can be drawn back. But here is one more thing that you can do to maximize daylight in a room with a south facing window:
Using these two techniques in conjunction, the curtain and the mirror, you can get enough light to fill a room evenly and beautifully. Once the contrast is dealt with, the fact that a southern window gets so much light becomes useful: even a very small window will provide enough light to fill the room most days.