Medical experts say sniffing poppers, commonly sold in gay clubs across the UK, can cause lasting damage to the eyes.

A study has revealed the liquid chemicals, which are made up of various alkyl nitrites, can affect the macula within the eye, which can cause sight impairment.

It’s been reported that some users have experienced permanent sight loss from only one dose, and others have found their sight returns to normal only after they have stopped using the substances.

Writing in the journal Eye, doctors have urged for greater awareness about the potential side effects.

It is illegal to sell poppers for human consumption but they are often sold in sex shops and gay venues as “air fresheners”.

Last month, a study by the Lesbian and Gay Foundation (LGF) and the University of Central Lancashire showed gay people in England and Wales are seven times more likely to take illegal drugs than the general population and that 1 in 5 have used poppers in the past month.

The LGF says people need to be aware of the dangers of using poppers and has described it as a potential “public health issue” to the BBC.