Coloured lenses


Many children and adults suffer from visual discomfort when reading. This can affect reading fluency, concentration and comprehension and can cause rapid fatigue. We would describe these symptoms as 'Visual Stress' or 'Meares-Irlen Syndrome.'

How can we help?

For over 20 years now, we have known that using colour can help relieve symptoms of reading difficulty and visual stress. Colour is used (either in the form of a coloured overlay or tinted lenses) to change the appearance of print to improve reading comfort and speed.

It is important to note that the most effective coloured overlay may not be the same colour as the optimal precision lenses.

What tests are needed?

Eye Examination

Every child who displays problems with reading should initially attend their optometrist for a full eye examination. If glasses are required these can eventually incorporate coloured lenses for visual stress if necessary.

Overlay Assessment

Following the eye examination, your optometrist may recommend an assessment with coloured overlays. These sheets of thin, transparent plastic are placed over written text to change the colour of the background to see if there are any benefits.

Colourimetry Assessment

If overlays are beneficial, the optometrist may suggest Colourimetry as the next stage. This may result in the prescribing of glasses with coloured lenses.

Where can these tests be done?

Overlay assessments are available in all our practices.  We have 4 practices across Scotland with specialist colourimeters, you can book a colourimetry assessment in the following practices:-

Colour overlay


What would I notice?

Common symptoms of visual stress include:-

• Movement of printed text
• Blurring of print
• Letters changing size or shape
• Patterns in the print (sometimes described as rivers or worms)
• Haloes of colour surrounding letters or words
• Tiring easily whilst reading
• Headaches or visual discomfort
• Red, sore or watery eyes

Who is likely to suffer from Visual Stress?

Approximately 5% of the population are severely affected by visual stress and 20% to a lesser degree. Visual stress can affect anyone, at any age, but it is more common in conditions including:-

• Dyslexia
• Dyspraxia
• Photosensitive Migraine
• Photosensitive Epilepsy
• Autism

Visual Stress is not the same as dyslexia but is more common in those who are dyslexic. People who fail to read because of visual stress are frequently misdiagnosed as dyslexic. For this reason it is important that the existence of visual stress is identified at an early stage.