Evaluation of visual stress symptoms in age-matched dyslexic, Meares-Irlen syndrome and normal adults

Osuagwu, Uchechukwu L., Alanazi, Saud A., & Alanazi, Mana (2016) Evaluation of visual stress symptoms in age-matched dyslexic, Meares-Irlen syndrome and normal adults. International Journal of Ophthalmology, 9(4), pp. 617-624.

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To examine the prevalence of dyslexia and Meares–Irlen syndrome (MIS) among female students and determine their level of visual stress in comparison with normal subjects.


A random sample of 450 female medical students of King Saud University Riyadh (age range, 18 - 30 years) responded to a wide range of questions designed to accomplish the aims of this study. The detailed questionnaire consisted of 54 questions with twelve questions enquiring on ocular history and demography of participants while 42 questions were on visual symptoms. Items were categorized into; critical and non-critical questions (CQ and NCQ) and were rated on four point Likert scale. Based on the responses obtained, the subjects were grouped into normal (control), dyslexic with or without MIS (Group 1) and subjects with MIS only (Group 2). Responses were analysed as averages and mean scores were calculated and compared between-groups using one way analysis of variance to evaluate total (TVSS = NCQ + CQ), critical and non-critical visual stress scores. The relationship between categorical variables such as age, handedness and condition were assessed with Chi- Square test.


The completion rate was 96.8% and majority of the respondents (92%) were normal readers, 2% dyslexic and 6% had MIS. They were age-matched. More than half of the participants had visited an eye care practitioner in the last 2yrs. About 13% were recommended eye exercises and one participant experienced pattern glare. Hand preference was not associated with any condition but Group 1 subjects (3/9, 33%) were significantly more likely to be diagnosed of lazy eye than Group 2 (2/27, 7%) and control (27/414, 5%) subjects. The mean ± SD of TVSS responses were 63 ± 14 but it was 44 ± 9 for CQ and 19 ± 5 for NCQ. Responses from all three variables were normally distributed but the CQ responses were on the average more positive (82%) in Group 2 and less positive (46%) in Group 1 than control. With NCQ, the responses were equally less positive in Group 1 and 2 than control. Group 2 subjects showed significantly higher TVSS (P = 0.002), NCQ (P = 0.006) and CQ (P = 0.008) visual stress scores than control but no difference between Group 1 and control subjects, was observed for all scores (P > 0.05, for all comparisons).


The prevalence of dyslexia and MIS among Saudi female students was 2 and 6%, respectively. Critical questions performed best for assessing visual stress symptoms in dyslexic and MIS subjects. Generally, students with MIS were more sensitive to visual stress than normal students but dyslexics were more likely to present with a lazy eye than MIS and normal readers.

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ID Code: 92334
Item Type: Journal Article
Refereed: Yes
Keywords: Dyslexia, Strabismus, Meares–Irlen syndrome, Binocular Vision
DOI: 10.18240/ijo.2016.04.24
ISSN: 2227-4898
Subjects: Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > OPTOMETRY AND OPHTHALMOLOGY (111300) > Ophthalmology (111301)
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
Current > Schools > School of Optometry & Vision Science
Copyright Owner: Copyright 2016 International Council of Ophthalmology
Deposited On: 27 Jan 2016 23:03
Last Modified: 01 Jun 2016 23:49

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