Unusual findings from a Brazillian research study confirmed what many of us already know: alcohol affects how attractive we view members of the opposite sex, and more alcohol we injest, the more attractive we find other people. But this phenomena seems to effect men more, and longer.
The researchers used facial symmetry to determine how attractive the men found their female partners, and easily determined that more alcohol equaled less ability to determine symmetry. This would explain why men will sometimes pick up women they normally wouldn't find attractive when drinking with friends in a bar.
But another study undertaken also in 2008 found that the beer goggle effect wore off with female drinkers by the morning after, whereas men were still seeing their partners from the night before - and any person of the opposite sex - in a more favorable light.
Source: Svoboda, Elizabeth. 2009. "Her Body on Booze." Men's Health (10544836) 24, no. 4: 104-106. Consumer Health Complete.