An 11-year-old girl has stumped doctors after going blind over a period of just 10 weeks.
Becky Cranmer was diagnosed with optic neuritis, the inflammation of the optic nerve, a rare condition that is normally cured by steroids.
But the treatment hasn't worked for Becky.
Her family say medics believe the swelling may be caused by a lack of vitamins, but can't work out why her body seems to reject them.
Becky's problems began during the summer holidays, before starting Denton Community College in Manchester.
Her mother, Angela, told the Daily Mail: 'We were away in the caravan when we noticed she started asking to have the lights on, even when it was really sunny outside.
'She's horse-mad and she always had her head in a horse magazine. but that week she didn't pick one up She said her eyes were too tired.'
Angela took her daughter to an optician, who advised them to go to hospital. She spent the next six weeks having tests at the Royal Oldham Hospital and the Royal Manchester Children's Hospital.
Becky has since undergone blood tests, a lumbar puncture and three MRI scans.
'They've exhausted all the possibilities, so if anyone knows or can suggest anything, anything at all, we're willing to give it a try,' said Angela.
Mrs Cranmer said doctors couldn't see if the optic nerve wass damaged due to the swelling, but if it's unaffected she could potentially get her sight back.
Angela, who also has a son Colin, 13, has given up her job as a teaching assistant to look after Becky. She goes to school three days a week where she has one-to-one support.
'She's 11 now and she wants to be out with her mates but that's just not possible,' said Angela.
'She's lost her independence and it's really scary for her, it's a different world.'
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