Scotopic Sensitivity Syndrome/Irlen Syndrome is not a learning disability. It is a complex and variable condition that can sometimes co-exist with learning difficulties or a learning disability.
Scotopic Sensitivity Syndrome, also known as Irlen Syndrome, is described as a visual-perceptual problem that exists independently of any optical deficit's. The source of the problem is linked to the encoding and decoding of visual information by the nervous system. The Centre for Special Education and Disability Studies use the following description:
It is a visual-perceptual processing dysfunction which causes problems with reading, study and writing/spelling. It has been related to a retinal-sensory after-imaging effect, possibly associated with the magnocellular visual pathway, which may cause an overlapping of letters and words between consecutive eye fixations when reading or writing.
Scotopic Sensitivity Syndrome cannot be detected by standard visual, educational and medical tests. It may also be detected in addition to the need for corrective prescription lenses.
The following difficulties can be related to Scotopic Sensitivity/Irlen Syndrome:
- letters and/or words unstable in any way (moving, blurring, fading etc)
- seeing streaks of white ('rivers')or flickering or flashing on the page
- print goes blurry, fuzzy, moves or disappears after a short time
- letters or words have halos or shadows
- print doubles or distorts
- eyes get tired, sore, watery, sandy, scratchy or itchy after reading, but eyesight is good or has been corrected with spectacles
- sensitivity to glare, to fluorescent lighting, flickering lighting, computer lighting
- the page is 'too bright'
- history of scotopic sensitivity within the student's family background
- a discrepancy between achievement on orally presented information and achievement on visually presented information (writing, reading etc.) whereby the student's written documents present a much poorer picture of the student's abilities than does the student's verbal provision of information
- poor spelling, writing which is difficult to read, poor use of grammatical construction
- slow reading rate - inability to read notes or words in groups; may see half to one word at a time, causing tracking problems and inability to skim
- poor depth perception - inability to accurately judge distance or spatial relations; unsure on stairs, escalators, ball sports or driving.
Further information and related links:
References
- Centre for Special Education and Disability Studies (2002), Irlen Syndrome, Newcastle University, Australia
- Irlen, H. (2002), Reading by The Colors, Berkley Publishing Group, USA
- The Irlen Institute, USA
- Irlen Dyslexia Centre, Melbourne
- Whiting, P. (1994) Irlen Coloured Filters for Reading: A Six-Year Follow-up. The Australian Journal of Remedial Education, 25(4) 14-21.