Scientists believe they have worked out a formula to calculate how "beer goggles" affect a drinker's vision.

The drink-fuelled phenomenon is said to transform supposedly "ugly" people into beauties - until the morning after.

Researchers at Manchester University say while beauty is in the eye of the beer-holder, the amount of alcohol consumed is not the only factor.

Additional factors include the level of light in the pub or club, the drinker's own eyesight and the room's smokiness.

The distance between two people is also a factor.

They all add up to make the aesthetically-challenged more attractive, according to the formula.

The formula can work out a final score, ranging from less than one - where there is no beer goggle effect - to more than 100.

Read the full story: news.bbc.co.uk