In November, Sheffield University student Lauren Platts bought a cheap bottle of what she thought was vodka, for £5.99.

She says the man in the off-licence jokingly said 'It will blind you'. Miss Platts said she laughed at the time but now she thinks he was not far wrong.

After drinking about a third of a bottle mixed with lemonade she spent the next two days unable to get out of bed.

After speaking to Trading Standards officers, she now knows it was not vodka at all.

"I had the worst migraine ever, I was extremely sick, with blurred vision. On the second day I wondered whether I'd ever get better."

Two months on and the 21-year-old from Chesterfield in Derbyshire still has blurred vision and regularly loses peripheral vision.

"I've been sent home from work because of the vision problems. It's really scary. I think I might have it for good, but I'm just grateful to be alive or not completely blind," she said.

Media playback is unsupported on your device Media caption Miss Platts said she felt lucky not to have been blinded

Miss Platts now knows what she drank was industrial alcohol.

Often methylated spirit is mixed with bleach to change the colour of the alcohol, so it resembles vodka.

Other chemicals like isopropanol, used in cleaning fluids, and chloroform, used in pesticides, have also been found in bogus brands.

Police and Trading Standards say the illegal industry is becoming more sophisticated.

In Boston, Lincolnshire, in July, five men died in an explosion at an industrial unit. Police later confirmed they had found a filtration plant for making fake vodka within the small building.

They're getting better at forging the bottles and labels. But the contents are lethal Ed Binsted, President of the British Bottlers Institute

Miss Platts' symptoms are classic signs of someone who has consumed methanol and other chemicals, often used by illegal brewers.

She is among a growing number of vodka drinkers, especially students, who are seeking out cheap brands. Universities in Sheffield and Leeds reported a spike in counterfeit alcohol in student areas in November.

The student welfare officer at Sheffield University, Matt Denton, said they had posted warnings on their website.

Students have described feeling extremely ill after drinking what they thought was cheap vodka, and some have suffered memory loss.

Trading Standards teams across the country say they are seizing illegal alcohol every week.

A consultant at Lincoln County Hospital, Vikas Sodiwala, said patients were turning up at casualty departments showing similar symptoms to Miss Platts - dizziness, nausea, stomach pains, vomiting and blurred vision.

He said they had bought it at off-licences, drank it at a party, or even got it from car boot sales.

"Methanol can attack the optic nerve at the back of the eye. This is what can affect a person's vision and in some cases make them blind," he said.

"I'm hearing this is now a nationwide problem and other colleagues in the East Midlands are reporting an increase in patients who don't realise they've consumed industrial alcohol not vodka."

A spirits industry expert has warned the bootleg factories where the fake vodka is made are a disaster in the making.

Ed Binsted, president of the British Bottlers Institute, said: "These places are like timebombs. Look at what happened in Boston with the five men who died in the unit there where fake vodka was found.

"These places are popping up all over the country. The industry needs to be one step ahead of the bootleggers - they're getting better at forging the bottles and labels. But the contents are lethal."

Miss Platts' story is featured on BBC Inside out in the East Midlands, at 19:30 GMT on Monday.