Visual Stress Assessment

What is visual stress?

The most common type of specific learning difficulty is specific reading difficulty and this is often called dyslexia. Dyslexic children are usually poor at spelling and may seem intelligent in conversation, but have trouble with written language.

One of the most common visual anomalies in dyslexia is poor or unstable co-ordination of the two eyes (binocular instability). This can cause eyestrain, visual distortions, or headaches and may slow reading and discourage children from prolonged reading.

The use of coloured filters is a controversial topic and it is widely agreed that coloured filters should not be thought of as a treatment for dyslexia.  About one in five people with dyslexia may also have a co-occurring condition that causes them to experience visual distortions (e.g., words appear to move or blur) and/or eyestrain and headaches from a page of text. Some of these children report a reduction in their symptoms with coloured filters and this condition has been called Visual Stress (also known as Meares-Irlen Syndrome, Irlen Syndrome, or Scotopic Sensitivity Syndrome)

Signs of visual stress may not be immediately obvious, but have you noticed the following?

  • Your child reads slowly and without fluency
  • Your child tracks the words with a finger
  • Your child seems to find reading difficult after about 10 minutes

These are some of the symptoms which could result in your child struggling through school, not making the progress they are capable of and losing their self-confidence along the way.

The first step is to book a full eye examination for your child. This is free of charge for all school aged children. Under the NHS, children are entitled to attend for an eye exam every 6-12 months.  In advance of your child’s appointment for Visual Stress Assessment, we ask you to complete a Visual Stress questionnaire

Our team will check your child’s eyesight thoroughly.

We may then carry out more specialised tests to check eye co-ordination and ability to change focus. Where necessary, we will advise you about glasses and/or eye exercises.

If eyesight problems are not the cause of the symptoms your child is having, the next step is an overlay assessment. Coloured overlays have been shown to help some children experiencing visual stress. Using Thomson Colour Screener software for the assessment, your child then selects a coloured background that appears to make the print on the computer screen more comfortable and easy to read.

If there is an improvement in the reading speed of 5% or more, a coloured overlay is used for a few weeks to see if it continues to help improve reading speed and accuracy. If the consensus between your child, you and their teacher, is that the overlay is helping, you can return for colorimetry. Colorimetry is the measurement of colour using an Intuitive Colorimeter.

The Intuitive Colorimeter was scientifically designed to present sequentially the colours in colour space, thereby allowing your child to swiftly identify the precision colour to best alleviate their symptoms. Under Carmel’s supervision we aim for your child to select the optimal colour for visual comfort. The final optimal colour can be prescribed in Cerium Precision Tinted Lenses which may reduce or eradicate symptoms of Visual Stress 

Coloured lenses are also much more convenient than overlays for board and computer work.

 NHS Eye Exam FREE for all school age children

Visual Stress Assessment £55.00 

  • (60 mins appointment or 2 x 30 mins )


Coloured Overlay               £10.00

Colorimetry Appointment £36.00 (30 mins) 

Precision Tint  £170.00 (Frames + Lenses separate) Lenses may be covered by NHS