By Jane Elliott
Health reporter, BBC News
Ben's reading has improved
Ben Osborne-Harris is a bright teenager, who has sat two of his GCSEs a year earlier than normal.
But just a couple of years ago, the 13-year-old London schoolboy was struggling badly - because he could not read properly.
"He just found it incredibly difficult to grasp reading at school," said his mother Gaynor.
"His reading age was well below average. When he got homework I had to help him read it and when he sat his Sats tests at 11 (in English, maths and science) he had to have someone read the questions to him.
"I initially thought he was dyslexic and took him to be tested but, because he could not read very well, the test did not work and they could not determine whether he was or was not."
On a routine visit to the optometrist she mentioned the problem and they suggested testing Ben for a condition called scotopic sensitivity, a type of visual disturbance, which can easily be overcome or dramatically improved with the simple use of coloured filters.
It worked, and Ben has leapt ahead taking parts of his drama and maths GCSE exams a year early.
London optometrist Prakash Rughani, who treated Ben, said scotopic sensitivity is thought to affect half of all children with learning difficulties, amounting to around a million children in the UK.
Testing is available at a number of optometrist clinics throughout the UK, but not on the NHS and needs to be funded privately. The cost of the checks and coloured glasses, if needed, is around £150-£175.
Mr Rughani said the treatment can also help with another eye condition, visual stress, that can also slow progress at school.
"This is essentially hyperactivity of the brain, resulting in visual disturbances and headaches which may cause problems with reading.
"In this case, the colour tints help by making the brain relax.
"The patients are unaware, because they have nothing to compare with that they have these difficulties, but it stops them from reading efficiently," he said.
'It's tragic but true that many children struggle unnecessarily at school."
Mr Rughani said many children who could benefit from this treatment are not doing so, because it is not being picked up.
"We get patients all the time who don't know this sort of help is available from their optometrist."
Ben gets called Elton John because of his coloured glasses
Mr Rughani, of Visioncare Medical Eye Centre, said colorimetry testing can bring about a dramatic improvement.
'Different people's eyes respond to the varying wavelengths produced by different colours.
"If an initial 'rate of reading' investigation suggests that a child may benefit from colorimetry, we will dispense a colour overlay or for them to try," he said.
Over 100,000 tints are on offer and they can be fitted into glasses if found to be useful.
Gaynor said she believed the colour filters had made a difference to her son's vision. "The improvement in his education was staggering.
"'Now can do his homework unaided and is so much happier, even with the rest of his GCSEs looming!'
"I don't think I will ever be able to say for definite it was because of the colours, but it is a reasonable coincidence. And if I didn't think it made a difference to his reading I wouldn't keep paying for the glasses."
"Ben says he still notices a difference.
"He said the words were a bit clearer with the colours. They call him Elton John at school because of the different colours in his glasses.
"He has had them in rose pink and bright green - now deep blue so the needs do keep changing.
"It does make me wonder whether there are other children this might help with."
Dr Susan Blakeney, optometric adviser for the College of Optometrists agreed that studies have shown that the filters may benefit some pupils with learning difficulties.
But she added: "The patient should make certain that they have had a thorough eye examination to ensure that there are no other problems which may be contributing to difficulties reading."