This may not help much, but I had a similar experience recently. I was bothered by the fact that one of my headlights was slightly duller than the other. Taking Sundeep's advice, I tried to take off the clips and clean it, but found it had been cheaply repaired after a previous accident or something. It wasn't even properly airtight.
Some guy in the Trading Post was selling good headlights for $40 each, so I grabbed one of those and haven't looked back (not that I've even driven the car since then. hehe).
Jack Travis, E-Series Acting President
1989 Ford Fairmont Ghia turbo/GL replica (underway)
1994 Eunos 800M
1990 Ford Laser S