"Acne sufferers may be offered laser treatment after the success of trials.

A session lasting five minutes led to improved skin for three months.

Dr Tony Chu, a consultant dermatologist at Hammersmith Hospital in West London, called it a major advance."

N-LITE is a laser using yellow light to destroy the bacteria that causes acne. Inside this bacteria is a substance called porphorine which is photosensitive. When activated by either blue or yellow light, it creates a chemical reaction releasing oxygen, which kills the bugs.

In the past, blue light has been used to treat acne with some success. But this does not penetrate the skin very far leaving some bacteria unaffected, so the results are temporary. Yellow light penetrates the skin more deep1y, killing all the bacteria, with much longer-lasting results.

A recent clinical study showed that from a single N-lite treatment, which takes 15 minutes, the number of acne lesions was reduced by more than 50 per cent in two weeks and continued reducing for up to three months after treatment.