Desk Review of Frequency of Types of Astigmatism and Their Relationship to Asthenopia

Abstract

Background: Astigmatism is one of the most prevalent refractive errors and a major contributor to asthenopia symptoms such as headache, visual fatigue, and double vision. Its clinical impact varies with refractive type and meridional orientation, yet the specific associations between astigmatism subtypes and asthenopia in young adults remain insufficiently clarified. Objective: The study aimed to determine the frequency of refractive and meridional types of astigmatism in young adults and to evaluate their association with asthenopia symptoms, with emphasis on headache and double vision. Methods: A descriptive cross-sectional study was conducted among 186 participants aged 18–35 years at a university-affiliated clinical setting. Visual acuity and refractive status were assessed using standardized optometric procedures, and astigmatism was categorized into simple, compound, and mixed subtypes, as well as with-the-rule, against-the-rule, and oblique orientations. Asthenopia symptoms were evaluated with a structured questionnaire. Associations between astigmatism subtypes and symptoms were analyzed using chi-square tests and odds ratios with 95% confidence intervals. Results: Compound myopic astigmatism was the most common subtype (45.7%), followed by mixed (20.4%) and compound hyperopic (19.9%). With-the-rule orientation predominated (45.7%). Asthenopia was reported by 63.4% of participants, with headaches in 118 (63.4%) and double vision in 108 (58.1%). Compound myopic (OR 2.6, 95% CI 1.4–5.0, p=0.005) and with-the-rule astigmatism (OR 2.4, 95% CI 1.3–4.6, p=0.004) were significantly associated with symptoms. Conclusion: Compound myopic and with-the-rule astigmatism disproportionately contribute to asthenopia in young adults. Early screening, accurate classification, and timely correction are essential to reduce visual discomfort and improve quality of life.