Colourimetry Assessment

Visual Stress

Visual Stress is a term used to describe visual discomfort and perceptual distortions in printed text and is suffered by some people who struggle to read. Symptoms can be experienced in varying degrees from simple fatigue to difficulties when looking at text.

All or some of the following symptoms may be present in Visual Stress:

  • Movement of printed text
  • Blurring of print
  • Letters that change size or shape
  • Tiring easily whilst reading
  • Headaches or visual discomfort

The existence of visual stress and its treatment with coloured filters remains controversial due to a mixed body of evidence. The relative contribution of visual stress and binocular instability with other factors(e.g. phonological deficit, verbal short-term/working memory, rapid autonomised naming, magnocellular deficit) is poorly understood.


Dyslexia (usually diagnosed by an Educational Psychologist, not an Optometrist) is an umbrella term for many sensory problems that may affect learning. Visual symptoms are sometimes associated with dyslexia, and by treating such symptoms, it can help the child read more comfortably and may improve their perception of text. This may help them to benefit from teaching and contribute to an improvement in reading performance.

Fewer than one in five people with dyslexia may have visual stress and find Precision Tinted glasses helpful.


Migraine attacks have many triggers factors; however 40% may be visually induced by flickering light, patterns, or reading. These attacks, in such cases, may be helped with precision tinted lenses.

colourimetry tests in Uxbridge

Contact Us

If you or your child has learning and/or reading difficulties, our School Vision Assessment would be an ideal way of exploring the various factors that might be contributing to the problem.

The Intuitive Colorimeter is a very simple instrument that is used to determine the exact colour precision tint that may give relief from perceptual distortions in Visual Stress.

Solutions such as glasses, eye exercises, coloured overlays, as well as precision tinted lenses are all ways of improving the reading performance of the individual. These often result in greater fluency and comfort when reading, developing one’s learning as well as providing increased self-esteem.