Environmental factors, particularly educational behavior, are more strongly linked to shortsightedness than is cognitive performance.
Several studies have shown that higher educational level is linked to a greater prevalence and severity of myopia. Other studies have suggested an association between shortsightedness and intelligence. The question remained was “What is the better predictor of shortsightedness, cognitive performance or educational attainment which is directly related to known risk factors of myopia including nearwork and reduced outdoor activity?”
In a recent publication in IOVS researchers from the Gutenberg University Medical Center of Mainz / Germany used data from the population-based Gutenberg Health Study (GHS) to analyze the association between myopia, intelligence and educational level in a large adult German cohort aged between 40 and 79. They used the Tower of London (TOL) test to measure cognitive performance. The 20-minute test assesses cognitive ability by mentally planning ahead and problem solving. Level of education was assessed using questionnaires and the highest level achieved was translated to years spent in school and post-school professional or academic education. Non-cycloplegic autorefractometry measured the refraction.
Considered in isolation both educational level and intelligence were correlated to myopic refraction. However, in a linear mixed model, years spent in education significantly predicted myopia (β = -0.14; t = -7.55; P < 0.001), whereas cognitive performance did not (β = -0.017; t = -1.26; P = 0.207). There was a significant effect of age on the spherical equivalent (β = 0.049; t = 9.89; P < 0.001).
The results suggest that level of education rather than intelligence is more important for development of myopia. This finding is in line with other publications that emphasize environmental factors to be more relevant for the current myopia epidemic than genetic factors. Level of education is a surrogate of educational behavior, including nearwork and less time spent outdoors which have been linked to myopia in previous research. “To put it crudely, myopia is not the ophthalmic sign of intelligence, rather it marks the striver”, says Alireza Mirshahi.
Invest Ophthalmol Vis Sci. 2016 Oct 1;57(13):5230-5236. doi: 10.1167/iovs.16-19507.
Myopia and Cognitive Performance: Results From the Gutenberg Health Study.
Mirshahi A1, Ponto KA2, Laubert-Reh D3, Rahm B4, Lackner KJ5, Binder H6, Pfeiffer N7, Unterrainer JM4.
1Department of Ophthalmology, University Medical Center Mainz, Germany 2Dardenne Eye Hospital, Bonn, Germany.
2Department of Ophthalmology, University Medical Center Mainz, Germany 3Center for Thrombosis and Hemostasis, University Medical Center Mainz, Germany.
3Preventive Cardiology and Preventive Medicine/Center for Cardiology, University Medical Center Mainz, Germany.
4Medical Psychology and Medical Sociology, University Medical Center Mainz, Germany 6Medical Psychology and Medical Sociology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
5Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center Mainz, Germany.
6Institute for Medical Biostatistics, Epidemiology and Informatics, University Medical Center Mainz, Germany.
7Department of Ophthalmology, University Medical Center Mainz, Germany.
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