Scientists have found that alcohol clouds women’s judgement more easily in a study of 100 men and women at Roehampton University.

Subjects were asked to rate pairs of faces while some drank strong vodka and tonic and others had a soft drink.

Symmetry is known to be linked to attraction, so individuals had to look at pairs of faces on screen and judge whether they thought they were symmetrical or asymmetrical.

Researcher Lewis Halsey said: “People that had drink tended to be less good at noticing if a face was asymmetrical, they often saw it as being symmetrical when it was asymmetrical.”

The study, published in the Addiction Journal, showed women to be particularly bad at the task.

Hasley said alcohol had less of a beer goggle effect on men because they are more visually orientated and more stimulated by what they see than women.

Hasley added: “What we have shown is that people’s ability to detect symmetry is part of the explanation for the beer goggle effect.

“The consequences could be considerable. A lot of people say they met their partner when they were drunk. Are their marriages shorter or longer lasting? Does it change the nature of the relationship?”

A previous study at Bristol University found that people appear more attractive to both sexes after drinking alcohol – and it only takes a pint and a half of beer.

But some studies contradicted this finding, with researchers at Leicester University saying: “”There was no difference – the men were just as undiscerning as ever.”