this link was one of the first in a google search.
funny quote:
"Understanding mechanisms behind changes in beer tastes is important because the world beer industry is hoping to save money by storing, shipping and selling beer in less expensive clear glass," Forbes said. "Producers of Miller Genuine Draft, for example, already do that by adding a chemically modified hop compound to the beer. We have found evidence that Miller beer is still photochemically active, but it doesn’t make the same free radicals, and so those can’t lead to bad-tasting skunky thiols as quickly."
Corona beer also is sold in clear bottles, but manufacturers do not used a modified hop product, he said. Instead, they usually keep their bottles boxed to exclude light and encourage drinkers to add a slice of lime to improve the odor.