Health - When sight can be tiring and painful

Amanda Hargreaves

Imagine what it is like not to be able to read without getting a headache from trying to focus on the print, which seems to dance and blur before your eyes.

Or even how it feels not to be able to meet someone's eyes and hold their gaze, because you are seeing two faces and four eyes.

If you are one of the 15% of the population who suffer from a condition called binocular instability, then that is the reality - but you may not even realise you have it.

Binocular vision involves the control and co-ordination of both eyes.


This is affecting a sizable number of our children
Nadia Northway
Visual Stress Clinic

Although each eye sees a separate image, these images are blended in the brain into one single picture.

The eyes are rarely completely straight. In most of us, they drift slightly and this is controlled without us even noticing.

If our eyes drift too much, this can cause headaches and discomfort, especially when reading.

The result is delayed processing of information at the most basic level.

It is a condition that makes reading and learning arduous.

Yet it can be cured simply and cheaply with eye exercises and spectacles.

'I want to see properly'

Megan Slater, 15, is now undergoing treatment after years of failing at school: "I want to be able to see properly - I don't want to be frustrated.


WHAT TO LOOK FOR
If your child is having difficulties at school, check if the following apply:
They complain of tiredness or headaches after reading
They complain of the print becoming blurry
They find it easier to read on a coloured background
They rub their eyes after reading for a while
They often lose their place when reading aloud
They often misread short words

"When I get frustrated the teachers tell me to calm down and I just get really angry."

Brigid Sundaram remembers having problems when she was at university, studying biochemistry.

"I had to read a lot of papers with tiny print," she said.

"After 20 minutes I'd usually be asleep in the library, it was exhausting.

"I've always had to work harder than anyone else to achieve the same results."

Brigid struggled for years at school and university before finally getting the help she needed.

The reason is that the condition isn't easily spotted in a routine eye test.

You could have 20/20 vision and still have binocular instability.

Diagnosis a problem

According to Nadia Northway, who runs the Visual Stress Clinic at Glasgow Caledonian University, diagnosis is a problem.

She is one of only 1,500 specially trained orthoptists who can spot the subtleties of binocular instability.

Orthoptists only practice in hospitals and are therefore hard to access.

On the High Street, only some optometrists have the special training required to diagnose the condition.

Funding is another key issue.

Professor Bruce Evans, director of research at the Institute of Optometry, has been campaigning for proper funding for the detailed eye test required to diagnose binocular instability.

He said: "We have had sympathy from politicians, but so far no promises of proper funding for this. It has been a very frustrating process."

Significant problem

There is no doubt in the mind of Nadia Northway about the impact of the condition.


WHAT TO DO
If you suspect you or a member of your family may have Binocular Instability and/or Visual Stress (Mears-Irlen Syndrome:
Get a regular eye test (they are free now on the NHS) at least once very two years if you are symptom free
Children should have their eyes tested once a year, as their sight changes all the time
If you suspect that you have a problem even though you are already wearing glasses, or even if you are given the all clear in a routine eye test, ask your GP to refer you to the orthoptics department of your local hospital
There you can be properly assessed and given treatment if necessary
Alternatively, ask about optometrists in your area who have a particular interest in reading problems.

"This is affecting a sizable number of our children," she said.

"Given that one in 16 people leave school with inadequate literacy skills and at least half of those may have vision problems, we should be campaigning in the streets about this."

And the condition also runs in families, so if the problem isn't spotted, you and your relatives could spend years battling against this hidden disability without knowing what the problem is.

After all, how does a five-year-old child know how reading should feel?

The child would probably just assume that everybody finds it tiring and painful.

Brigid Sundaram realised that all three of her children had the same symptoms as herself, and sure enough they were all diagnosed with Binocular Instability and Visual Stress, also known as Meares-Irlen Syndrome.

Both problems often co-exist and have very similar symptoms.

And the scale of the problem is still revealing itself.

According to research that Nadia Northway is currently carrying out on adults with literacy problems, as many as 80% appear to have binocular instability and/or visual stress.

"When you extrapolate from those figures what that means for the general population, it's likely that as many as one third of us may have one or other of these conditions" said Nadia.