Not all windows look the same and on some houses you will have round or half round windows that you will want to get shutters for. These can also be called arch top shutters and they can be made out of any material.
When you have a half round window at the top of a wall, you have a choice of whether to do anything with it at all. Usually it will be a good source of light and as it is up so high, it does not sacrifice any privacy if you let it be as is. Many people like the additional light and will choose to not cover it up with blinds or shutters.
Some people want the complete look though, and want to get half round shutters to cover that window just like all the other ones on their house. Most shutters now days are decorative and you might even put them above a window just for looks even though their is no window there.
Wooden house shutters ideas are used to make a house look better and give it a sense of style. More folks are installing decorative shutters rather than real working ones now days because of the added curb appeal. If you like the look and you have some half round windows, you might investigate the cost to see if they are worth the investment.