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Frequently Asked Questions

No, Irlen Syndrome is an underlying issue which can contribute to reading and learning difficulties.

A simple assessment at an Irlen Clinic or with a qualified Irlen Screener is the only way to have an accurate diagnosis. There are a selection of Irlen self tests on this website to assist you in identifying if you or your child have signs & symptoms of Irlen Syndrome.

Irlen Syndrome can cause similar symptoms to Dyslexia and is sometimes referred to as visual processing dyslexia. It often co-exists with Dyslexia.

No. Some people with this condition may not have learning difficulties but can have problems with light sensitivity, brightness, glare, headaches, migraines, eye strain and fatigue.

Yes. Irlen Syndrome may cause difficulties with depth perception, judging distance and clumsiness.

Irlen Syndrome can contribute to issues with: Headaches, Migraines, Anxiety, Sensory Processing Disorder, Epilepsy, ADD/ADHD, Autism Spectrum Disorders, Chronic Fatigue Syndrome, Fibromyalgia, Bi-Polar Disorder, Depression and Irritable Bowel Syndrome.

No, Irlen Syndrome is not an optometric issue but a difficulty with visual perception, and how the brain processes what the eyes see. Before a person visits an Irlen Clinic it is recommended they have their eyes checked with an optometrist. An Irlen assessment will assess the brain and an optometrist assessment will assess the eyes.

Irlen Spectral Filters can eliminate or significantly reduce glare on a page, and the distortions or distractions which may occur with the print. They allow people to keep their position when reading, improve word recognition, increase reading fluency, allow for better comprehension and improve concentration. They can reduce eyestrain and fatigue making reading more comfortable.

Yes, Irlen Syndrome can cause headaches and migraines.

Yes, research has demonstrated that Irlen Spectral Filters can assist people with photosensitive Epilepsy.

Yes. Research demonstrates Irlen Syndrome affects 33% of people with ADD/ADHD. Having Irlen Syndrome can contribute to lack of concentration, reading avoidance, behaviour problems and disinterest or poor attitude to learning. Other difficulties can include: distracting others, low self esteem, frustration, withdrawal in the learning environment and lack of motivation.

Irlen Spectral Filters work by filtering out the specific colour in the light spectrum that an individual is particularly sensitive to. This has a calming effect on the brain and increases a person’s ability to process visual information clearly.

No. Every person’s colour is different. An Irlen assessment will determine the precise colour/s required to assist each individual’s perceptual issues.

No. They assist by eliminating or reducing visual distractions and distortions on the page when a person is reading. The Irlen Spectral Filters do not replace the need for reading instruction and remediation. Once a child can see the words clearly without discomfort or distortions, they can begin to learn to read.

Yes. Irlen Syndrome and the effectiveness of Irlen colored overlays and Irlen Spectral Filter Lenses has been the subject of over 100 research studies encompassing the disciplines of education, psychology, and medicine.

An Irlen Assessment is a two-step process:

  1. The first testing session can be carried out by either a certified Irlen Diagnostician or an Irlen Screener. This initial assessment determines whether a person has Irlen Syndrome, how severe the problem is and whether they can be helped with Irlen coloured overlays. The correct coloured overlay is determined at this time.

  2. The second testing session can only be carried out by a certified Irlen Diagnostician. The second assessment is only for individuals who show moderate to significant improvement with coloured overlays. In this session, the aim is to determine the precise wave lengths of light causing a person’s perceptual problems, by using a limitless number of colour filter combinations. The precise colour is then prescribed to be worn as glasses or contact lenses.

Certified Irlen Diagnosticians and Irlen Screeners are trained to assess people for Irlen Syndrome. Optometrists, behavioural optometrists and eye specialists cannot test for this condition. They are trained to assess vision and not perception.


An optometric check is recommended before having an Irlen Assessment. The optometrist will assess a person’s eyes to determine if any optical issues are present. An Irlen Assessment will assess how the brain processes what the eyes are seeing. A person can have an optometric problem as well as a perceptual problem. Optometric glasses will not remove the symptoms of Irlen Syndrome and Irlen Lenses will not correct an optometric problem.

Research has demonstrated that the colour of the Irlen tint must be precise to be effective. A colour that is not quite correct can be ineffective and the wrong colour can cause an increase in symptoms. Sunglasses will simply reduce glare and do not specifically remove the particular wavelengths of light that cause the symptoms of Irlen Syndrome. The Irlen lenses are specific whereas sunglasses are not.

Signs of Irlen Syndrome when reading include: slower reading fluency, poor word recognition, difficulty keeping position, poor comprehension, lack of concentration, moving closer to or further away from the page, reading from awkward angles, cannot sit still, eye strain, rubbing eyes, blinking, squinting, opening eye wider, shading the page, frustration, reading avoidance, yawning, complaining of headaches, fatiguing easily.


Yes, Irlen Syndrome can still be present in good readers. In these cases, signs may include a reluctance to read, the need to go back and re-read what they have already read, an inability to read for a long time before getting a headache or sore eyes. Their comprehension may not reflect their reading ability or they may even go to sleep while reading.

A child with Irlen Syndrome may read fluently and accurately yet more of their energy and effort will be directed at reducing the brightness of the page, maintaining print clarity and trying to keep their position while reading. They are using an excessive amount of energy to maintain their concentration and their brain does not have enough energy then to remember what they have read, therefore their comprehension can be affected.

In most cases the overlay is not required when the Irlen Spectral Filters are worn. In some severe cases, they are still needed, but only when reading on white paper.

The Irlen overlay is just an approximation of what tint colour will be required to be worn as Irlen Spectral Filter Lenses. The Irlen Spectral Filter tint may be similar or very different to the overlay colour. It is important to be assessed by an Irlen Diagnostician to determine the precise tint colour required to assist with a person’s perceptual issues.

Irlen overlays only filter the light from the page you are directly looking at. Spectral filters filter both direct and peripheral light and so have a more calming effect on the brain. This helps to further reduce symptoms such as sore eyes, headaches, migraines and print distortions.

Some schools do preliminary Irlen testing on students who are having difficulty with reading, concentration or behaviour because they have a teacher who is a trained Irlen Screener. Some schools have come across enough children to identify some of the symptoms in children who are having learning difficulties.

Your school may not have mentioned it because there aren’t many children identified at the school, or it may be that Irlen Syndrome is not included in the DSM (Diagnostic and Statistical Manual of Mental Disorders). Irlen Syndrome is often overlooked by professionals such as Optometrists, Speech Pathologists, Psychologists or Occupational Therapists who come into the schools to do assessments.

Some teachers know about Irlen Syndrome because they have come across it either through having children in their class diagnosed with the condition or their own child may be diagnosed with Irlen Syndrome. Other teachers still have not heard about Irlen Syndrome or come across it in their classrooms. Part of the reason is because the Department of School Education does not mention it during teacher training. Other teachers know about Irlen Syndrome, but are discouraged by the Department of School Education from recommending testing to parents for reasons unknown.

People with Irlen Syndrome are sensitive to the flickering created by fluorescent lights. Fluorescent lights are extremely bright compared to natural light and incandescent lights, and this creates an overstimulation of the visual pathways in some people with Irlen Syndrome. The flickering light frequencies cause the brain to become overstimulated resulting in increased signs & symptoms of Irlen Syndrome.


The Departments of Education will recognise Irlen Syndrome as a dysfunction that may require accommodations such as coloured paper, natural lighting and not fluorescent lighting but they do not have the qualified staff to test for Irlen Syndrome.

Irlen Spectral Filters can help some children with Autism and Asperger Syndrome. The Irlen Filters are a piece of the puzzle but they are not a cure. The filters help with:

Sensory Overload caused by bright lights, fluorescent lights, and sunlight. Lighting is stressful and this can result in behaviours such as shading eyes,  wanting to wear a hat inside, poor eye contact, and physical symptoms such as anxiety or headaches.

Environmental Distortions where the individual sees the world in a distorted fashion. Objects are blurry, moving, changing, and can disappear. People may look frightening, stairs may look like a slide without steps, and walls and floors may swing and sway. Misperceptions can cause difficulties with sustained attention, eye contact, gross and fine motor coordination, ability to interpret facial expressions and poor social skills.

Print Distortions make learning or reading difficult. The individual may have good or even advanced reading skills but has trouble with reading comprehension or experiences strain and fatigue when reading or doing other activities

Irlen Syndrome affects approximately:

  • 12-14% of the general population
  • 46% of individuals with reading and learning difficulties
  • 33% with ADHD
  • 33% with autism
  • 55% with head injuries, concussion or whiplash

School counsellors are not trained to identify the symptoms of Irlen Syndrome and are only required to refer parents to health professionals such as psychologists, GPs, optometrists etc.