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Visual Stress And Colour Assessments

What is visual stress? (Also known as Meares-Irlen Syndrome)

Visual stress is caused by an over stimulation of the visual cortex. Sufferers find black text on a white background can provoke symptoms, such as;


• Movement or blurring of print
• Letters becoming darker or fading
• patches of colour appearing on the page
• colours or patterns seen in the text
• glare from the page

Symptoms are individual and can be different for everybody. Visual stress is more likely to be present in  anyone who has Dyslexia or Dyslexic tendencies, but can be present independently.

A pattern glare test can be used to confirm a person is suffering from Visual Stress. Visual Stress can be alleviated by colour.

Overlays & Colorimetry

Colour can help alleviate visual stress by calming the visual cortex and allowing the reader to perceive the text in a natural way. 


Overlays are sheets of coloured perspex which are laid over black and white text to see if colour can benefit the reader. There are twelve overlays to choose the optimum colour from. Should a coloured overlay be chosen, the patient should use it in all reading for a few weeks to ascertain a sustained benefit. Overlays can be very useful for young children who may find it difficult to choose the optimum colour during a Colorimetry assessment.


Colorimetry is carried out using a Colorimeter. The patient can choose the most effective colour from over 100,000 colour combinations. The colour is then made into Precision Tinted Lenses to enable the wearer to use their optimal colour for other activities such as computer use and interactive white boards.

Our Colour Service


• Eye Examination
A full eye examination is important for everybody and in particular those suffering with reading difficulties. An eye examination can rule out many other problems with the eyes which may be causing or contributing towards any difficulty. Behavioural problems (with the eyes) in particular can contribute to reading difficulty.

• Pattern Glare Test
A pattern glare test will be carried out for any individual with reading difficulty. This involves looking at a series of black and white patterns to see if visual distortion is present and to what degree.

• Overlay Assessment
Depending on the age (and other factors) of the sufferer we may carry out an overlay assessment. We will usually do this if the patient is a child younger than ten years old. The overlay assessment will be carried out by one of our colour experts to determine specific symptoms of visual stress and the benefit colour is likely to offer the patient. This is an inexpensive way to see if colour will be helpful and is a much easier method of choosing for younger patients.

• Colorimetry Assessment
Colorimetry is carried out for adults, older children and younger children with a sustained benefit from overlays.  The Intuitive Colorimeter works by passing coloured gels in front of a UV lamp and has over 100,000 different colour combinations to relieve visual stress. The optimal colour is chosen by a process of elimination in which the colour, saturation and hue are independently adjusted for the patients comfort. The colour is then made into precision tinted lenses for the wearers comfort and convenience.

​To find out more or to book an appointment please contact  Emma at Havant or Krystle at Park Gate.

Vista Mesh lenses can also help with visual stress and migraine. Please contact us for further information.

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