These websites have useful information. The ones near the end are put up by optometrists in the UK who are testing for colour using a somewhat different procedure than Irlen Screeners and Diagnosticians. However, it does show that they are aware that colour makes a difference. You can also type in Irlen Syndrome, Scotopic Sensitivity Syndrome or Visual Stress and find many more sites.

• Irlen Alberta: www.irlenalberta.ca (Nola Stigings, Certified Irlen Diagnostician)
• Irlen Institute: www.irlen.com (many research articles listed on website)
• Reading & Writing Consultants Inc: www.readingandwriting.ab.ca
• Irlen Dylexia Centre: www.dyslexiaservices.com.au
• The Dyslexia Diagnostic and Irlen Clinic: www.irlenwa.com.au/faq.htm
• Irlen Centre North West: www.irlen.org.uk
• Irlen Centres U.K.: www.irlenuk.com
• My World is not Your World: www.hale.ndo.co.uk/index.htm
• Rebecca Madl: www.help4teachers.com/irlen.htm
• David Accola – headaches: www.readingandlight.com
• Autism Society: www.autism.org/irlen.html
• Learning Disabilities Online: www.ldonline.org  (enter Irlen Syndrome in search box)
• Wikipedia: wikipedia.org/wiki/Scotopic Sensitivity Syndrome
• Irlen Centre, Colorado: www.irlencolo.com
• The Irlen Centre, Ottawa, ON: www.irlencentre.ca
• Amazon: www.amazon.ca/LightBarrier-Understanding-Mystery-Syndrome/dp/0312320280
• OK in Health: okinhealth.com/articles/Irlen-Syndrome-BC.html
• Irlen Syndrome Screening in Pennsylvania: www.irlen-pa.com
• Visual Stress: www.essex.ac.uk/psychology/overlays
• Visual Stress and Dyslexia: www.dyslexic.com/vision
• You Tube Irlen Syndrome – A Teen’s Summary www.youtube.com/watch?v=9N5qbMFtKQ4
• A colour filter for your computer -  www.musatcha.com/software/ColorFilter