A Norwich woman has told of her lucky escape after being warned she was close to suffering permanent eye damage and possibly even blindness because of an infection caused by her repeatedly sleeping with her contact lenses in.

Wearers of contact lenses are told to always take them out at night, but Katie Richardson, 24, from Dereham Road, had been wearing soft monthly disposable lenses since the age of 14 and they were so comfortable she often forgot she was wearing them and slept with them in.

But one morning she could not open her eye and she had to be rushed to hospital for emergency treatment, where she was told it was lucky she had not seriously damaged her sight.

She said: 'When I woke up with the very sore and red eye, I thought at first it was conjunctivitis, because I had that before.

'But the eye kept getting sorer during the day and in the end I went to see my GP who told me that I had to go to the eye hospital at the Norfolk and Norwich University Hospital.

'The eye specialist at the hospital diagnosed me with microbial keratitis, an infection of the cornea, the front part of the eye where lenses sit, which meant I had a fungus in my eye.

'The specialist told me my eyesight had been deteriorating rapidly and things could have got a lot worse if I hadn't been treated quickly – there was even a risk of losing my eyesight. He told me the infection was caused by overuse of contact lenses.'

She was prescribed steroid eye drops to be taken every five minutes for the first three hours, then half-hourly through the night and hourly for the next day. She also wore a patch to protect the eye as she recuperated.

'The steroid drops in my eye stung like hell and it was like a burning sensation,' she said.

Eventually, Miss Richardson, who is single and an account manager at Media Jems PR company in Costessey, recovered, but the experience left her scared and grateful the infection had been treated in time.

Left untreated, it can lead to permanent visual damage and in extreme cases, blindness.

She said: 'Since the infection I have never kept my lenses in overnight. I had become complacent so it was my own fault and it served me right. I had been warned previously that I had been wearing the lenses too long. If you play with fire, you get burned.

'It has certainly taught me not to mess with my eyes and not to take them for granted.

'It really shook me up. Had I been aware of the risks, I would have been more vigilant.'

She is now considering corrective laser eye surgery.

Parwez Hossain, a senior lecturer in ophthalmology at the University of Southampton eye unit, said significant numbers of eye cases could be avoided if people took the time to clean and store their lenses properly.

He said: 'Contact lenses are one of the leading causes of corneal infections, most stemming from abuse of the way they should be cared for.

'These include poor hand hygiene – you must thoroughly wash your hands before putting in and taking out contact lenses – storing them incorrectly, wearing them for too long or reusing disposable lenses.'

Microbial keratitis develops quickly and it isn't always apparent something is wrong, he added, because wearing lenses lowers sensation in the cornea, making the eye less sensitive to discomfort.

'Wearers may not feel all the features of early infection. The pain will start as the infection takes hold, generally getting worse once the lens, which was affording some protection, is taken out.

'Leave it out for a day or two and sensation returns to the cornea – then it really begins to hurt.'

A Dutch study in 1999 found that people who left their lenses in overnight were almost 20 times more likely to develop microbial keratitis.

Have you survived a rare infection? Call reporter David Bale on 01603 772427 or email david.bale2@archant.co.uk.