One thing I do is simply slow down and try to make sure of what I am doing. I also have a clip-on sun visor that is made out of the same thing sunglasses are, and that helps a lot.
Right now I am waiting on a shipment of Gunnar's (glasses). I am getting both a pair for at the computer since I am sitting in front of two each day for work and a pair of sun glasses as going into work I "drive into the sun".