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Colorimetry is the process of examining colour to alleviate Visual Stress.

Approximately 1 in 20 of the population suffers from the effects of visual stress and it is more common/ problematic in those with dyslexia.  Diagnosis and correction can often help prevent frustration and low self esteem, especially in children who may be under-achieving.

Visual Stress

Coloured Overlays

Tinted Glasses

What is Visual Stress?

In recent years, vision scientists have identified the condition of visual stress as a cause of persistent eyestrain and loss in reading fluency. The condition, which is related to light sensitivity disorders such as migraine and epilepsy, can be responsible for distortions on a printed page. Visual Stress can be a major contributor to poor reading problems and typically becomes evident in children as they start to read more closely packed text. This problem can continue into adulthood making reading uncomfortable and tiring.  


Signs of Visual Stress

Classic Symptoms of Visual Stress include - when reading: words 'move'; losing place, skipping lines or skipping words; the page is very bright; rapid tiring - and when writing: difficulty tracking across the page, work is poorly laid out; difficulty copying text from board or screen.

How can Colour Help?


Scientific research has shown that visual stress can be reduced using coloured filters. These filters can be placed directly on a page (overlays) or worn in glasses (precision tints). The colour is specific to each individual and has to be carefully selected.  The colour of an overlay is unlikely to be the same as the glasses.


Coloured overlays are useful initially but if benefit is derived from them, a full examination with an Intuitive Colorimeter is recommended. An Intuitive Colorimeter is an instrument which allows many colours of different depths to be presented and assessed for the effect that they have on reading. The coloured tint will allow reading to become more fluent and comfortable. It may also be beneficial for other circumstances such as computer use and copying from a blackboard.


How to Arrange a Colorimetry Assessment

If you think you or your child might have symptoms of visual stress then you should arrange a colorimetry assessment. A standard eye examination is also useful as sometimes symptoms of visual stress are aided by prescription glasses and/or eye exercises.


A colorimetry assessment involves an initial short telephone consultation, followed by a face-to-face examination as required.  All assessments are undertaken by Dr Ross Henderson.  Ross is a member of the society for coloured lens prescribers who have a code of conduct and continuing education requirements.



  • Initial telephone consultation   - Free

  • Overlay Assessment                   - £40

  • Colorimetry Assessment            - £70

  • Precision Tinted Lenses from*  - £159

* depends on prescription requirements​

Prior to any consultation, we ask that our Colorimetry Questionnaire be completed and returned to us at

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