scotopic sensitivity syndrome

What is Irlen syndrome?

People with Irlen syndrome cannot read comfortably. The words are not clear and easy to see. They may blur, move or change. These distortions may also affect how things look in the environment. There is no typical Irlen syndrome profile. The symptoms vary from person to person.

What are the symptoms of Irlen syndrome?

Helen Irlen, who discovered this condition in the early 1980s, identified six groups of symptoms experienced (singly or in combination) by many people with reading difficulties. They include:

Light sensitivity

Bothered by glare, fluorescent lights, sunlight or car headlights. Discomfort or difficulty working in a brightly lit room.

Contrast

Difficulty reading black print on white paper. The white may be bright, glary, uncomfortable to look at and may compete with the words.

Print

Difficulty reading print, numbers or music. Words can blur, merge together, wobble, move, double, or even disappear.

Span

Unable to see groups of letters or words clearly at the same time. Only one word or part of a word is clear while the rest is faint or blurry.

Concentration

Problems concentrating on reading or writing. Becomes restless, tired or takes frequent breaks.

Depth

Inability to judge distance and spatial relationships accurately. May bump into things, have difficulty with ball games and stairs.

How does Irlen syndrome affect children (and adults)?

Children (and adults) with Irlen syndrome have to put more effort and energy into reading because they see the printed page differently from the proficient reader. Constantly adapting to distortions from print and/or the white background causes strain, tiredness and discomfort and limits the length of time they can read and maintain comprehension. If they keep going, they may get sore eyes, headaches and, in some cases, nausea.

Irlen syndrome may affect reading and writing, attention span, energy level, motivation and work production. Children with Irlen syndrome react in different ways. Some don't give up on learning, but develop compensatory strategies such as taking frequent breaks, developing keen listening skills and memory, and choosing subjects that don't involve much reading. Others do give up, avoiding reading situations by pretending to read, misbehaving or being a truant.

Irlen syndrome is a visual-perceptual problem. It is not connected to eye defects so a person with Irlen syndrome may be wearing prescription glasses and/or have carried out vision exercises and still have problems. These problems appear to occur in the visual processing pathways that take messages from the eye to the brain. If these pathways are out of step with each other, print looks distorted.

The Irlen method and filters

Helen Irlen found that many of the distortions described above were reduced or stopped by the use of coloured filters. The tint varied from one individual to another and no one shade was linked to any particular type of distortion.

As a result, Irlen developed a method and technology to diagnose and prescribe. It involves an extensive diagnostic process to find out whether someone has this problem and, if so, which of the many symptoms that comprise the syndrome are present for that individual.

Once the symptoms have been identified, the person then undergoes a detailed and lengthy (up to two hours) assessment to determine which combination of tints (worn as glasses) will eliminate those symptoms, enabling the person to see the printed page clearly, comfortably and free of distortions. The page will still look white but it will be a comfortable white.

The result is a pair of filters specifically prescribed for that individual which overcomes the debilitating effects of Irlen syndrome. Tinting occurs in a laboratory with a computerised spectrophotometer to ensure the tint is the one prescribed. A slight difference could render the filter ineffective so precision is essential. An optometric prescription will be added if the person has been prescribed one.

Sunglasses or tinted lenses supplied by an optometrist are NOT Irlen filters.

Suggestions for parents

There are children who cannot see print clearly. The brightness of the page will make reading uncomfortable. Some of these children may be reading at or above their chronological age level. Others may be considerably behind their peers and some may have a range of learning difficulties.

Vision screening at school fails to detect a large number of children with visual/perceptual problems. Any child who is having difficulty concentrating on reading or learning to read should be referred in the first instance to an optometrist or ophthalmologist.

If there are no optometric problems or if the visual-perceptual difficulties persist after optometric problems have been corrected, the child should be referred for Irlen testing. Following is a list of factors which can be used to identify and assist people with Irlen syndrome.

Check reading behaviours

Does the child skip words, lines or punctuation, re-read lines by mistake, read a word from the line above or below, confuse letters that look similar? Does the child leave off the ends of words, begin in the middle of words, or not even attempt longer words, read slowly word by word?

Check body language

When reading, does the child blink a lot, squint, open their eyes wide, vary the distance from the page, get up close, become restless, lose concentration, take frequent breaks? Do the child's eyes get sore, tired, do they water, get hot, look strained?

Check the paper colour

See if reading is easier on coloured paper or if covered by a coloured plastic overlay.

Check the lighting

Most (but not all) individuals with Irlen syndrome are sensitive to glare, such as sunlight and fluorescent light, particularly the 'cool white' type. In dimmer light the distortions and discomfort are reduced - in some cases they disappear altogether. If possible, allow the child to read and work in the type of lighting they find most comfortable. Where this is not feasible, allow the child to wear a cap in class with a brim to shade their eyes.

Check the cause and not the symptom is being treated

The child may be exhibiting behaviours that are the result of being placed in situations of continued frustration and failure. Trying to recognise or decode a word that goes blurry, moves, turns into a black blob or disappears, is an impossible task. 'Trying harder' or being given extra reading, exacerbates the situation.

There are many avoidance strategies children use from pretending to be working to misbehaving to not turning up at school. This is a natural human reaction to a painful situation. It is important that any response or treatment is targeted at addressing the underlying cause.

Conclusion

The large number of positive studies shows that Irlen filters improve the stability and clarity of print and reduce the stress (effort) and visual discomfort associated with reading. Surveys of Irlen filter users also suggest the filters can increase attention, enable reading strategies (such as decoding techniques) to be applied more effectively, and as a result, in most cases improve comprehension of print.

Where basic reading skills have not yet been developed, immediate benefits to reading performance may not be observed since the effects are related only to ease of visual processing, and not to other aspects of the reading process. Clearer print may make reading skills easier to develop, but these skills may need to be taught, and supplementary reading tuition may thus be necessary.

Further information and support

There are over 200 Irlen screeners in New Zealand. Click here to search for a New Zealand Irlen Diagnostic Clinic near you.

Original material provided by David Wardell, Irlen Diagnostic Clinic. Reviewed in October 2009 by everybody.