Any photographer worth their salt uses lens hoods. I have one for every lens. Flare (non-image-forming light) is more than just a line of round reflections in an image:
 

Even before the light source gets in the shot, it can still kill the contrast in an image, rendering the shadows too light:


Sometimes these murky shadows are unavoidable, but I try to minimize those situations. A lens hood makes more of the shots look like this: