Using coloured overlays and filters we can help alleviate symptoms of Visual Stress.


Visual Stress is a general term used for a number of conditions that can cause people to struggle with reading – these conditions may also be called Visual DyslexiaScoptic SensitivityMeares-Irlen or Irlen Syndrome and Binocular Amblyopia. Although sharing similar symptoms, Visual Stress can be differentiated from Dyslexia even though many Dyslexia sufferers will also experience Visual Stress. It is not uncommon for children suffering from Visual Stress to be suspected of suffering from Dyslexia. The condition is estimated to be present in about 40 % of poor readers and in 20 % of the general population in varying degrees.


For those suffering from the condition it can be very difficult to read blocks of text, particularly black text on a sharp, white background. Words and letters may move across the page or swap around, halos may appear around words and text can appear to flow down a page like a waterfall. In some cases the brain is able to ‘fix’ these issues, but the reader will get eyestrain or severe headaches when reading as they try and compensate. Many thousands of individuals who find reading tiring and unpleasant, unknowingly experience Visual Stress. They have to work harder than their peers to achieve the same outcomes, often with extra tuition. Many could be helped by overlays or Precision Tinted Lenses. It is therefore essential that every child who struggles to read is referred to an optician who can undertake a full eye examination and check for the presence of Visual Stress.

The cause of Visual Stress is not known and there is no formally agreed diagnosis for the various Visual Stress conditions. Fortunately, multiple studies, along with our own experience, have shown that coloured filters can be of considerable benefit for sufferers – changing the background colour on which the text is read can have an immediate and powerful effect, making text comfortable to read and stopping the distortions and discomfort.

Visual Stress is believed to severely affect up to 5% of the population and up to 20% of the population to some degree. Whilst it can affect people of all ages, it is particularly important to detect it in children – many young sufferers are unaware that what they are seeing is unusual and it can lead to them underperforming at school. Awareness of Visual Stress can vary in schools and it can be helpful the know the symptoms to look out for.

The Sufferer Might Notice:

  • Words appear to move around on the page.
  • The words appear blurred or surrounded by halos.
  • Reading causes eye strain or headaches.
  • Tiring easily whilst reading.
  • The page appears to be very bright, so words cannot be seen properly.
  • They struggle to keep their place when reading text hence may use a finger as a marker.
  • Frustration and low self-esteem.


A Parent or Teacher Might Notice:

  • They are often closing their eyes or looking away.
  • Rubbing eyes whilst reading.
  • Eyes become red or begin watering after a few minutes of reading.
  • Frequently varies reading position and becomes restless.
  • Rapidly becoming tired whilst reading.
  • Loses place easily, skipping lines or words whilst reading aloud.
  • Has difficulty tracking across the page, work is poorly laid out.
  • Has difficulty copying text from the board or another book.
  • Tries to avoid reading.


If you suspect that you, or your child, might be suffering from or displaying these symptoms, then it is worth investigating this further – the symptoms of Visual Stress can be easily addressed and many have described the effects as ‘life changing’ when their condition is identified and helped.

We always recommend you have an eye examination first – this allows us to remedy any underlying sight or muscle weakness, in some cases the sufferer may simply have undiagnosed short or long sightedness. We can then perform the Visual Stress test, using a variety of testing techniques to identify a coloured overlay that will provide the most help when reading. We then let them try out the overlay at home, work or school and book a follow-up appointment two weeks later to see how they are getting on.

We normally recommend coloured overlays to begin with, they offer more flexibility and subtlety, particularly for children at school who do not wish to stand-out. We can also recommend coloured lenses for glasses – which may be combined with a prescription lens if this is beneficial. In many cases the colours for the lenses are different to those of the overlay. Coloured Overlays are used widely both in the classroom and by vision professionals in practice. Moderate to significant improvements in both reading rate and accuracy are not uncommon when the optimum overlay is prescribed. Overlays are coloured sheets of robust transparent plastic that are placed over a page of text when reading. The assessment pack consists of 12 overlays of different colours. The colours have shades that differ systematically. The variety of shades is sufficient to provide a shade optimal for each individual. Assessment involves the presentation of each overlay in turn for comparison with others placed beside it. The assessment can be carried out by one of our experienced opticians.

If you would like more advice, please telephone or e-mail us with any queries and we will be more than happy to help.