- An = number of units of alcohol consumed
- S = smokiness of the room (graded from 0-10, where 0 clear air; 10 extremely smoky)
- L = luminance of 'person of interest' (candelas per square metre; typically 1 pitch black; 150 as seen in normal room lighting)
- Vo = Snellen visual acuity (6/6 normal; 6/12 just meets driving standard)
- d = distance from 'person of interest' (metres; 0.5 to 3 metres)
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.
Nathan Efron, Professor of Clinical Optometry at the University of Manchester, said: "The beer goggles effect isn't solely dependent on how much alcohol a person consumes, there are other influencing factors at play too. "For example, someone with normal vision, who has consumed five pints of beer and views a person 1.5 metres away in a fairly smoky and poorly lit room, will score 55, which means they would suffer from a moderate beer goggle effect."
Some how I missed the opportunity to be a researcher on this study.