Screen Time, Short Sleep, and Family History Drive Myopia in Young Iraqi Adults

More than half of the young adults walking into three major Iraqi eye hospitals are myopic, and nearly two-thirds carry some degree of astigmatism, according to one of the largest clinic-based refractive studies ever conducted in the country. The research, published in Frontiers in Ophthalmology, analyzed the right-eye refraction of 4,340 consecutive attendees aged 18 to 37 at Ibn Al-Haitham Teaching Eye Hospital in Baghdad, Imam Hussain Specialized Eye Complex in Karbala, and Al-Hakeem Teaching Hospital in Najaf, collected over two years from February 2024 to February 2026.

The numbers are striking. Using a spherical equivalent threshold of minus 0.50 diopters, myopia was present in 51.2 percent of the analytic sample, hyperopia in 37.0 percent, and astigmatism, defined independently by cylindrical power of at least 0.50 diopters, in 66.4 percent. Because astigmatism was measured separately from the spherical refractive status, these categories overlap rather than sum to 100 percent. Notably, although 515 participants had an emmetropic spherical equivalent, every one of them had astigmatism of at least 0.50 diopters, meaning not a single person in the sample met the combined definition of no refractive error.

Severity tells its own story. High myopia, defined as a spherical equivalent of minus 6.00 diopters or worse, affected 13.0 percent of participants, while high astigmatism, a cylinder of 2.00 diopters or more, was present in 31.6 percent. High hyperopia was comparatively rare at 2.5 percent. Among the mutually exclusive principal-meridian profiles, pure myopia was the most common at 22.9 percent, followed by simple hyperopic astigmatism at 16.1 percent, simple myopic astigmatism at 14.9 percent, and compound myopic astigmatism at 14.0 percent.

Sex differences were pronounced. Myopia was more frequent among women than men, 53.6 percent versus 45.6 percent, while hyperopia showed the reverse pattern, 33.5 percent among women versus 45.0 percent among men. High myopia also favored women, 14.5 percent versus 9.5 percent, whereas high hyperopia favored men, 3.9 percent versus 1.8 percent. Astigmatism was only modestly different between the sexes, 67.5 percent among women and 63.9 percent among men.

To identify factors associated with myopia, the researchers standardized all refraction records to minus-cylinder notation before calculating the spherical equivalent, then ran multivariable logistic regression across the full sample. After adjustment, female sex carried an adjusted odds ratio of 1.32 for myopia, a positive first-degree family history of refractive error carried 1.46, and age 28 to 32 years carried 1.28 relative to the 18 to 22 reference group. Sleep duration of six hours or less per night was associated with an adjusted odds ratio of 1.73, and daily electronic-device use showed a clear exposure-response gradient, 1.30 for five to eight hours per day and 1.80 for more than eight hours, relative to one to four hours.

Occupational context mattered too. Compared with students, participants in office work had an adjusted odds ratio of 0.73 for myopia, manual workers 0.77, and unemployed participants 0.59. Student status, the authors suggest, may capture a bundle of sustained reading, intensive near work, prolonged indoor activity, and frequent device use, though they caution that work status is a broad social indicator rather than a direct measure of visual exposure. Governorate and urban versus rural residence showed no significant association with myopia after adjustment.

The severity-specific models revealed distinct patterns. Among participants with myopia, high myopia was associated with female sex, adjusted odds ratio 1.40, and was less frequent among rural residents, 0.57, and primary tablet users, 0.74. Among participants with hyperopia, high hyperopia was less frequent among women, 0.60, and those aged 28 to 32, 0.37, but more frequent in Karbala, among manual workers, 4.07, and unemployed participants, 4.11. Among participants with astigmatism, high astigmatism was strongly associated with sleep duration of six hours or less, adjusted odds ratio 2.83, and device use of more than eight hours per day, 3.07, while rural residents had lower odds, 0.49.

The authors are careful about interpretation. The study was cross-sectional and clinic-based, so the distributions reflect tertiary-clinic attendees rather than the general Iraqi young-adult population, and the 70 percent female predominance in the sample may itself reflect sex-related differences in care-seeking. Behavioral variables were self-reported and measured concurrently with refractive status, so they are treated as correlates rather than established causes. The absence of cycloplegic refraction, a limitation the authors acknowledge, may have shifted measurements toward myopia and masked hyperopia, particularly among younger adults with residual accommodation.

Still, the findings carry practical weight. The authors argue that the identified associations with sex, family history, sleep duration, electronic-device exposure, and work or study status can support targeted history taking, refractive assessment, counseling, and service planning for young adults in similar clinical settings. Family history, one of the strongest independent predictors, may represent both inherited susceptibility and shared household environmental exposure, and the authors recommend including it in clinical risk assessment.

What comes next? The authors call for population-based longitudinal studies incorporating cycloplegic refraction, ocular biometry, and standardized measures of near work and outdoor exposure to determine whether these associations hold at the community level and whether they are temporal rather than cross-sectional artifacts. For now, the study offers one of the most detailed multicenter clinical profiles of refractive error in young Iraqi adults, and a reminder that in the digital age, the optics of the eye may be shaped as much by lifestyle as by genetics.

Subject of Research: Refractive errors among young Iraqi adults

Article Title: Distribution and factors associated with refractive errors among young adults attending ophthalmic clinics in Iraq: a multicenter cross-sectional study

Article References: Distribution and factors associated with refractive errors among young adults attending ophthalmic clinics in Iraq: a multicenter cross-sectional study. (n.d.). https://doi.org/10.3389/fopht.2026.1904325

Image Credits: AI Generated

DOI: 10.3389/fopht.2026.1904325

Keywords: myopia, astigmatism, refractive errors, Iraq, young adults, screen time, sleep duration, family history, ophthalmology, cross-sectional study, Distribution, factors