Irlen spectral filters or Irlen lenses are coloured overlay filters or tinted lenses crafted specifically for the wearer and worn as glasses or contact lenses. They are intended to help people with the supposed perceptual processing difficulty known as Irlen syndrome, also known as scotopic sensitivity syndrome or visual stress, in which sensitivity to specific wavelengths of light provokes difficulty and discomfort when performing visually intensive activities such as reading. The existence of Irlen syndrome is controversial.[1] The Royal Australian and New Zealand College of Ophthalmologists (RANZCO) came out strongly against Irlen syndrome, saying there was no evidence the condition existed or the treatment of reading difficulties with Irlen lenses worked.[2] However, there is a small body of research supporting the use of colour to alleviate the symptoms associated with Irlen syndrome.[3][4][5][6][7][8][9]

Scotopic sensitivity syndrome

Scotopic sensitivity syndrome is said to be a visual-perceptual defect related to difficulties with light source, glare, luminance, wavelength, and contrast. According to Irlen, these difficulties lead to reading problems, eye strain, headaches, migraines, and other physical difficulties that can be alleviated by the use of person specific tinted lenses, known as Irlen spectral filters, worn as glasses or contact lenses.

The syndrome has six characteristics:

  1. photophobia
  2. eye strain
  3. poor visual resolution
  4. a reduced span of focus
  5. impaired depth perception
  6. poor sustained focus

Scotopic sensitivity syndrome is diagnosed by interviewing the client and by observing responses to certain visual tasks such as interpreting geometric figures and reading.[10]

History and research

The idea of page based distortion was initially suggested in 1980 by Olive Meares,[11] to improve the reading ability of people with a learning disability, specifically a certain type of dyslexia. Later this was taken further by psychologist Helen Irlen. The proposition by Irlen was made at the Annual Meeting of the American Psychological Association in 1983. At that time, there was little research made on the effect of tinted lenses. Irlen gained notable publicity demonstrating the efficacy of her method on television. Tinted lenses became a commercial success, and testing and prescribing centers were opened throughout USA.[12]

Diagnosis of Irlen Syndrome and treatment with Irlen Spectral Filters has been reviewed by the USA Medical Board, and has been determined as not the practice of medicine; it has also been reviewed by various USA Boards of Optometry and has been found to be inconclusive and not to be the practice of optometry. Binocular and accommodative anomalies may occur in conjunction with the syndrome, but are not considered to be the underlying physiological basis of the condition.[13][14]

Commercial claims of utility

According to Irlen, the lenses are supposedly used to treat a wide variety of problems that are associated with light sensitivity, discomfort and distortions, including head injury, concussion, whiplash, perceptual problems, neurologic impairment, memory loss, language deficits, headaches and migraine, autoimmune disease, fibromyalgia, macular degeneration, cataracts, retinitis pigmentosa, complications from an eye operation, depression, chronic anxiety and others.[1] She has also claimed that a treatment for scotopic sensitivity syndrome could help a number of incarcerated individuals and delinquent children.[1]

Criticism

The Irlen method has been criticised for being put to the market prior to serious research.[1] According to Helveston, the scotopic sensitivity syndrome and its treatment has, as a phenomenon, resulted in classic group behaviour and has the characteristics of a fad with a charismatic personality as a leader and the supporting evidence being mostly anecdotal—even though those with visual stress are spread around the world, mostly don't know each other, and have no interest in Helen Irlen, all of which conditions would need to be met to fulfill the criteria of group dynamics.[1] A 2002 study by Professor Arnold Wilkins at Essex University, though, indicates that there may be some benefit for reading difficulties [15], and also for people with migraines.[16]

See also

References

  1. 1 2 3 4 5 Helveston, Eugene M. (2004). "Tinted Lenses" (PDF). IDA Information Packet: 12–13.
  2. ↑ "RANZCO Position Statement: Irlen Syndrome" (PDF). The Royal Australian and New Zealand College of Ophthalmologists. Retrieved 24 July 2023.
  3. ↑ Chouinard BD, Zhou CI, Hrybouski S, Kim ES, Cummine J (July 2012). "A functional neuroimaging case study of Meares-Irlen syndrome/visual stress (MISViS)". Brain Topogr. 25 (3): 293–307. doi:10.1007/s10548-011-0212-z. PMID 22124535. S2CID 13065620.
  4. ↑ Huang J, Zong X, Wilkins A, Jenkins B, Bozoki A, Cao Y (June 2011). "fMRI evidence that precision ophthalmic tints reduce cortical hyperactivation in migraine". Cephalalgia. 31 (8): 925–36. doi:10.1177/0333102411409076. PMC 3132147. PMID 21622479.
  5. ↑ Noble, Jeanne; Orton, Michelle; Irlen, Sandra; Robinson, Greg (2004). "A controlled field study of the use of coloured overlays on reading achievement". Australian Journal of Learning Disabilities. 9 (2): 14–22. doi:10.1080/19404150409546760. ISSN 1324-8928. S2CID 144487363.
  6. ↑ Robinson GL, Foreman PJ (August 1999). "Scotopic sensitivity/Irlen syndrome and the use of coloured filters: a long-term placebo controlled and masked study of reading achievement and perception of ability". Perceptual and Motor Skills. 89 (1): 83–113. doi:10.2466/pms.1999.89.1.83. PMID 10544403. S2CID 26076221.
  7. ↑ Whiting, P., Robinson, G.L., & Parrot, C.F. (1994). "Irlen coloured filters for reading: a six year follow up". Australian Journal of Remedial Education. 26: 13–19.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  8. ↑ Wilkins, Arnold (2002). "Coloured overlays and their effects on reading speed: a review". Ophthalmic and Physiological Optics. 22 (5): 448–454. doi:10.1046/j.1475-1313.2002.00079.x. ISSN 0275-5408. PMID 12358317. S2CID 46738042.
  9. ↑ Wilkins AJ, Evans BJ, Brown JA, et al. (October 1994). "Double-masked placebo-controlled trial of precision spectral filters in children who use coloured overlays". Ophthalmic Physiol Opt. 14 (4): 365–70. doi:10.1111/j.1475-1313.1994.tb00126.x. PMID 7845693. S2CID 22931718.
  10. ↑ "Testing & Treatment". Irlen Institute. Retrieved 15 January 2013.
  11. ↑ Meares, O. (1980). Figure/ground, brightness contrast and reading disabilities. Visible Lang. 14, 13-29
  12. ↑ Silver, Larry B. (2004). "Theme editor's note" (PDF). IDA Information Packet: 12.
  13. ↑ Evans BJ, Patel R, Wilkins AJ, et al. (November 1999). "A review of the management of 323 consecutive patients seen in a specific learning difficulties clinic". Ophthalmic Physiol Opt. 19 (6): 454–66. doi:10.1111/j.1475-1313.1999.00465.x. PMID 10768028. S2CID 10063554.
  14. ↑ Scott L, McWhinnie H, Taylor L, et al. (March 2002). "Coloured overlays in schools: orthoptic and optometric findings". Ophthalmic Physiol Opt. 22 (2): 156–65. CiteSeerX 10.1.1.490.5596. doi:10.1046/j.1475-1313.2002.00009.x. PMID 12014489. S2CID 8778440.
  15. ↑ Scott, Lorna; McWhinnie, Hazel; Taylor, Lynette; Stevenson, Nicola; Irons, Peter; Lewis, Elizabeth; Evans, Marylyn; Evans, Bruce; Wilkins, Arnold (2002). "Coloured overlays in schools: orthoptic and optometric findings". Ophthalmic and Physiological Optics. 22 (2): 156–165. doi:10.1046/j.1475-1313.2002.00009.x. ISSN 1475-1313. PMID 12014489. S2CID 8778440.
  16. ↑ Evans, B. J. W.; Patel, R.; Wilkins, A. J. (2002). "Optometric function in visually sensitive migraine before and after treatment with tinted spectacles". Ophthalmic and Physiological Optics. 22 (2): 130–142. doi:10.1046/j.1475-1313.2002.00017.x. ISSN 1475-1313. PMID 12014487. S2CID 24753768.
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