Thousands of party-goers are risking going blind for using novelty contact lenses on Halloween, eye experts have warned.
The lenses, available online and in fancy dress shops, can cause ulcers, tears on the cornea, infections and permanent sight damage.
Contact lenses should only be given out by a prescription in the UK.
But novelty lenses can be bought and used without any safety checks being made on the eyes.
This means some people who have never used lenses before are damaging their eyes just by putting them in the wrong way – and have no idea of the dangers of poor eye hygiene.
Carrie-Anne Balloch, 21, from Leeds, was left in agony after wearing a pair of cat’s eyes contacts at a party last year.
She was forced to sleep with a wet towel over her eyes for two weeks after the pair she bought for £9.99 on eBay scraped the delicate skin on her cornea.
Miss Balloch said: ‘It was horrible and looking back now, I can’t believe I did it.
‘I bought the lenses on eBay and didn’t really think twice about their safety as loads of my friends have used them and been fine.
‘As soon as I put them in, I felt like my eyes were being scraped and I could hardly see as they were just streaming, but my friends said it would take a while to get used to them.
‘I’ve never worn lenses before so I didn’t know what I was feeling was my eyes being damaged.
‘They felt really thick and heavy on my eyes too.’
After a few hours the pain and discomfort became too much, and she was forced to take them out.
When she woke up the next morning, her eyes were bloodshot and puffy.
Miss Balloch was prescribed eye drops to try and soothe the pain.
‘I also had to sleep with a wet towel over my eyes at night as they would just sting like mad. It was about two weeks until they returned to normal,’ she said.
Dr David Allamby, a consultant eye surgeon, said he is concerned that people such as Miss Balloch are risking severe health consequences by using novelty lenses.
Contact lenses should only be fitted by a optometrist who measures each eye to fit the lenses and checks how the eyes respond, he said.
Poorly fitting lenses can lead to scratches or ulcers on the cornea, conjunctivitis, decreased vision and even blindness.
Mr Allamby, who founded the Focus laser eye clinic in London, said: ‘The eye is a very delicate area and to put something in that has been sold by anyone other than an eyecare professional is very dangerous.
‘Decorative contact lenses need to be treated in the same way as prescription contact lenses, with thorough guidance on how to put them in and follow up care.
‘It’s quite shocking that you can just pick these things up on the internet or in a fancy dress shop with no advice or aftercare.
‘I have seen some terrible cases of injuries from contacts and novelty ones aren’t likely to be of the same quality as those on prescription.
‘Even just putting them in incorrectly can lead to tears on the cornea, then bacteria breeds behind the lens which can lead to ulcers and ultimately blindness.
‘After a party, people might sleep in them which increases the likelihood of infection. They need to understand there is a risk of them permanently damaging their eyes.’
He explained: ‘Cosmetic contact lenses should be supplied only by or under the supervision of a registered optician or medical practitioner. This equally applies to lenses described as “eye accessories”.
‘Supervision requires the registered person to be present on the premises, aware of the procedure and in a position to intervene if necessary and the supplier must also make arrangements for the wearer to receive ongoing care.
‘Any sales of cosmetic contact lenses that do not meet these requirements are illegal under the Opticians Act.’
Miss Balloch is now urging people to think twice before putting in the party lenses.
She said: ‘What happened to me was really frightening and I can’t believe I could have permanently damaged my eyes.
‘I’m glad I took the lenses out when I did or I dread to think what could have happened to me. Now I tell my friends not to mess about with these lenses.
‘It’s just not worth the risk.’