I don't know why I took this picture... but it highlights the wires that run through the windshields (how many depends on the model) on the front of the airplane. These heat producing wires run between two pieces of glass so that not only can the pilots see (they won't frost/ice over), but also to provide bird strike protection. They are usually always "on" but can be turned up to high if necessary. Just in case this ice protection fails, there is a backup: some airplanes have some anti icing fluid that will spray over the window to clear a small portion of the window for landing (this would be under the "emergency" category).
And luckily, they are not usually this obvious. You hardly notice them.