Colorimetry is the process of examining colour to alleviate visual stress the signs of which include headaches and eyestrain, words appearing blurred, or the reading page or screen being very bright.

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.

How can Colorimetry 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 selected carefully.  The colour of the 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. This piece of equipment allows many colours 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 Appointment

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


A colorimetry consultation lasts approximately 45mins and is undertaken by Dr Ross Henderson. Dr Henderson is a member of the society for coloured lens prescribers who have a code of conduct and continuing education requirements.


At WJ Henderson Optometrists we have the latest computerised overlay testing software allowing accurate and fast overlay supply with you or your child’s name printed on the overlay. Overlays are a more affordable alternative to coloured lenses.