MOSCOW, RUSSIA - DOZENS of young revellers were blinded by a laser show at a dance music festival near Moscow last week and doctors fear the damage may be irreparable, the Kommersant daily reported.

'More than 30 people between the ages of 16 and 30 have ended up in hospitals in the capital with the same diagnosis - damaged retinas - since July 7,' the report said on Monday, quoting doctors.

One doctor told Kommersant: 'All of them have burnt retinas, you can see scars on them. The loss of eyesight in some cases is up to 80 per cent and it's unlikely it can ever be restored.'

Festival goers being treated in hospital said they were blinded when lasers intended to light up the night sky were trained on dancers.

'I immediately saw a black spot like the kind you get when you look at the sun,' said one of the patients.

The Aquamarine festival took place near the town of Vladimir, some 170 kilometres east of Moscow. -- AFP