Many men have used it to justify something they regretted in the morning - but they can forget the "beer goggles" excuse from now on, according to psychologists.

A study found that after drinking alcohol men actually see women as less attractive.

Booze also makes no difference to a man's ability to guess a woman's age, the research found.

Scientists asked a group of 240 men and women in bars and cafes to look at photos of women and comment on their age and attractiveness.

Half the participants used in the experiment had consumed alcoholic drinks, with effects rated as "relaxed and benign", "blunted and disinhibited", "boisterous and over-expressive", and "unambiguously drunk".

Some of the pictures of 10 young women aged 17 were digitally altered to make them appear younger or older. Make-up was also applied digitally to a number of images.

The findings showed that alcohol reduced the ability of women to guess the age of the photo models, but not men.

Both the effects of alcohol and prettifying a face with make-up had little effect on men's judgment.

Dr Vincent Egan, from the University of Leicester, said: "This study suggests that alcohol consumption and make-up use do not interfere with how old we perceive someone to be.

"Another interesting finding was that overall participants who drank alcohol actually rated all the women in the photos as less attractive, compared to the participants who hadn't drunk alcohol. This seemingly flies in the face of the commonly held notion of 'beer goggles'."

Participants consistently over-estimated the age of both mature and immature faces by an average of 3.5 years.

Reporting their results in the British Journal of Psychology, the researchers wrote: "Although alcohol limited the processing of maturity cues in female observers, it had no effect on the age perceptions of males viewing female faces, suggesting male mate preferences are not easily disrupted."

On a more serious note, they said the influence of alcohol should not be a mitigating factor in the case of a man accused of having sex with someone under-age.

"Our study suggests that even heavy alcohol consumption does not interfere with age-perception tasks in men, so is not of itself an excuse for apparent mistaken age in cases of unlawful sex with a minor," they wrote.