Your windscreen may not be completely clean. The problem may be the inside. I use Autoglym Fast Glass. This stuff really works. Use it on the inside with a really clean cloth and get that faint haze off. Also on the outside, after you've washed it. I'm also a stickler for never touching the inside of the windscreen with bare fingers, such as if its misted up. Use a clean wipey-thing. The oils in your skin always leave a mark.
As for headlights, get them clean as well. Even a very feint haze of dirt makes a big difference to the light spread. At the risk of sounding compulsive, I keep a wee bottle of water in the car to wipe the lights before leaving work at night. It makes a difference.
As for headlight bulbs, best on the market are the Phillips Extreme or Osram Nightbreakers. You can get them from Amazon or Ebay for about £15/pair delivered.