irlen syndrome symptoms

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What is Irlen Syndrome?

Irlen Syndrome (also referred to at times as Meares-Irlen Syndrome, Scotopic Sensitivity Syndrome, and Visual Stress) is a perceptual processing disorder. It is not an optical problem. It is a problem with the brain’s ability to process visual information. This problem tends to run in families and is not currently identified by other standardised educational or medical tests. 

It is important to realise that not all these symptoms are experienced by every single person. We are all different and each person has different symptoms which is why it is vital that an individual assessment be conducted by a qualified Irlen diagnostician.

Light Sensitivity

  • Bothered by glare from outside, including sunlight or on cloudy days, fluorescent lights, bright lights, and lights at night such as street lights or car headlights.
  • Some individuals experience feel exhausted or very tired, sleepy, dizzy, anxious, or irritable especially after a lot of reading or being in glary situations. Others experience migraines, headaches, mood changes, restlessness or have difficulty staying focused, especially with bright or fluorescent lights. Some experience stomach aches or nausea.

Reading Problems can include but are not restricted to:-

  • Poor comprehension
  • Misreading of words such as leaving off or changing the ending , and confusing little words such as saw and was, or, at and to.
  • Problems tracking from line to line and tracking across a line of text.
  • Shades the page to dim the light on the page or moves the page to a particular angle to change the light hitting the page.
  • Skips words or lines
  • Reads slowly or hesitantly
  • Takes breaks
  • Loses place
  • Avoids reading
  • Can only read for a short time.


  • Strain and fatigue
  • Tired or sleepy
  • Headaches or nausea
  • Fidgety or restless
  • Eyes that hurt, burn, become watery or dry, itchy, or sleepy eyes

Attention and Concentration Problems

  • Problems with concentration when reading and doing academic tasks
  • Often people can appear to have other conditions, such as attention deficit disorder, and are given medication unnecessarily.
  • Sometimes noise sensitivity or tactile sensitivity including irritability when there is a noise in the background or startles greatly when there is a sudden noise

Writing Problems

  • Trouble copying including but not restricted to losing place, incorrect copying or misplacing of words so written in the wrong order
  • Unequal spacing
  • Unequal letter size
  • Writing up or downhill
  • Inconsistent spelling

Other Characteristics:

  • Strain or fatigue from computer use and other technology such as phones, Ipads, Ipods
  • Difficulty reading music
  • Sloppy, careless math errors
  • Misaligned numbers in columns, or numbers written in the wrong order or place value
  • Ineffective use of study time and disorganisation
  • Lack of motivation
  • Grades do not reflect the amount of effort or do not reflect the verbal ability

Depth Perception

  • Clumsiness, tripping, stubbing toes, walking into things or people walking next to them
  • Difficulty catching balls on the full
  • Difficulty judging distances
  • Additional caution necessary while driving or poor parking


  • Words on the page lack clarity or stability; i.e., may appear to be blurry, moving, or disappear
  • Please see the distortion examples page.

You can  download PDF versions of the following Irlen Syndrome questionnaires:

Children’s Questionnaire
Adult Questionnaire
Teenager’s Questionnaire


Experience Irlen Syndrome


Learn more about Irlen Syndrome

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