According to the British Dyslexia Association and many Opticians, Visual Stress or Irlen Syndrome, is very common among people diagnosed with dyslexia.
According to the opticians round 35-40% of those with dyslexia have it. In the general population the prevalence is thought to be around 5-20%.
Visual Stress has many different names: Visual Dyslexia, Scoptic Sensitivity, Meares-Irlen Syndrome or Irlen Syndrome and Binocular Amblyopia.
Sufferers do not see a page of text the way it was written – with text all lined up neatly in rows. For them, the text may be swirling in circles, running down the page like a waterfall and whole words or individual letters moving.
Along with these illusions they may also be suffering from headaches, stomach aches, migraines and complain about feeling sick or their eyes hurt when they read.
Other clues are people who frequently yawn whilst reading or the use their finger to keep their place, lose their place when going from line to line or re-read the same lines, slow reading, rubbing eyes and poor comprehension.
If you think you, your child or a child in your class has visual stress you can use this handy screening test (and guide) as an initial assessment.
If the test highlights that there is a strong possibility of Visual Stress then there is a very inexpensive way of finding out if using a tint over the text will make a difference.
You should go to an Optician that is able to test for Visual Stress along with the standard sight test.
You may also find that there is a difference between the overlay tint you find most helpful and the glasses tint you find most helpful but that can be discussed with your optician, if necessary.