Guide to eye disease hallucinations

By David Fenton
BBC South health correspondent

Edna Scotson is nearly blind but sees lines of music before her

People who lose their sight will be given new guidance about a potentially frightening condition which causes hallucinations.

Patients have seen gargoyle faces appearing from the television, packs of black dogs in their homes and strange figures in wartime dress in their gardens.

Many fear they are becoming mentally ill or suffering dementia.

But in fact they have Charles Bonnet syndrome - a purely medical condition in which the brain tries to make sense of the signals from damaged eyes.

Typically patients see patterns of grids or figures, depending on which areas of the brain are being stimulated by the damaged nerves.

Charles Bonnet syndrome The disease is named after the Swiss naturalist who described the condition in 1760. He first documented it in his 89-year-old grandfather, nearly blind from cataracts, who saw men, women, birds, carriages, buildings, tapestries and scaffolding patterns.

Up to 100,000 people in the UK are affected by this. Edna Scotson, from Southampton, is one them.

She is a retired piano teacher who has now lost her sight almost entirely. But she still sees ghostly lines of music appearing before her, floating in the air or over the carpets.

"I saw these images of music," she said. "The stave of five lines, the notes formed perfectly, tied notes, dotted notes and sharps would appear.

"It's quite weird to see things like that. You don't like to say anything to people because they think perhaps you're losing your memory - so you just keep it to yourself."

'Too frightening'

Many people who lose their sight, through conditions such as macular degeneration, are not warned that they are likely to experience hallucinations.

In the past, doctors have felt it would be "too frightening" for them to be told. But when they do occur many patients are left wondering if they are losing their minds.

"People have been sent for psychiatric treatment as if they were beginning to suffer symptoms of dementia," said Tom Bremridge, of the Macular Disease Society.

"And no-one, neither the doctor nor the patient, knew that these were symptoms of macular degeneration. But it really is quite common and very distressing for people.

"Doctors will tell people they have an eye condition, what it is and what the result is as far as their vision is concerned, but they haven't considered the psychological effects - and especially hallucinations."

Now the Royal College of Ophthalmologists is issuing new guidelines to all eye specialists to explain the condition.

Dr Dominic Ffytche, a leading psychiatric specialist in the syndrome, said: "This is a very important new development.

"These hallucinations are often an unexpected consequence of the loss of vision, so the more knowledge that is out there the more patients will be able to talk about the phenomena and hopefully relieve the distress that they cause."