*Corresponding author: Muhammad Akbar Rashid, Independent Researcher  ABSTRACT Background and Objective: Refractive errors constitute a major public health burden in Pakistan, and astigmatism is among the most commonly diagnosed conditions in adolescents presenting to eye care facilities. Family history is thought to influence both whether astigmatism develops and how severe it becomes. This study aimed to establish whether a positive family history of refractive error is associated with more severe astigmatism among Pakistani adolescents. Methods: This cross-sectional analytical study was conducted using data collected over a six-month period in 2024. Sample size was calculated using G*Power 3.1 (80% power, two-tailed alpha of 0.05, anticipated odds ratio of 2.0), yielding a minimum requirement of 288 participants; 320 adolescents aged 10 to 19 years with astigmatism of at least 0.50 DC were enrolled through simple random sampling. Participants were stratified by family history status into those with a positive family history (FH+; n = 198) and those without (FH−; n = 122). Cycloplegic retinoscopy and subjective refraction were performed on all participants, and cylinder power was graded as mild (0.50–1.00 DC), moderate (1.25–2.00 DC), or high (≥ 2.50 DC). Axis type, astigmatism subtype, eye laterality, and best-corrected visual acuity were also recorded. Group comparisons were conducted using chi-square and independent-samples t-tests, with statistical significance set at p < 0> Results: A positive family history was present in 198 participants (61.9%). High astigmatism was significantly more prevalent in the FH+ group (38.9%) than the FH− group (19.7%; p < 0 xss=removed xss=removed> Conclusion: A positive family history of refractive error substantially increases the risk of severe astigmatism during adolescence, with higher cylinder power, bilateral involvement, and against-the-rule axis orientation as the principal distinguishing features. Incorporating family history into routine eye-screening protocols offers a practical, low-cost way to catch cases earlier and help prevent amblyopia in this population. KEYWORDS: astigmatism; family history; hereditary refractive error; adolescents; Pakistan; cylinder power; simple random sampling. INTRODUCTION Refractive errors remain the leading contributor to preventable visual impairment worldwide. The 2021 Global Burden of Disease study identifies refraction disorders, spanning myopia, hyperopia, astigmatism, and presbyopia, as the foremost cause of moderate and severe vision loss, with the greatest burden borne by young people in low- and middle-income countries such as Pakistan. [1] Within this category, astigmatism stands out. It results from unequal corneal or lenticular curvature across meridians, producing blur that cannot be resolved through accommodation. A 2023 systematic review pooling data from 125 independent studies reported astigmatism prevalence ranging from 8% to 62�ross age groups and ethnic populations, with consistent evidence that uncorrected astigmatism compromises vision, academic performance, and household finances. [2] Adolescence, defined by the World Health Organization as the period between ages 10 and 19, represents the most dynamic phase of visual development outside infancy, during which the eyeball continues to grow, the cornea continues to reshape, and refractive status can change substantially within months. [4] Pooled data across Global Burden of Disease sub-regions, analysed in 2022, confirmed that uncorrected myopia and astigmatism peak in the 6-to-17-year age bracket, with sub-regional variation attributable more to disparities in healthcare access than to underlying biological differences. [5] Undetected astigmatism in this period carries substantial consequences, ranging from amblyopia, in which the brain suppresses input from one or both blurred eyes, to impaired academic performance and lasting psychosocial effects. Cylinder power of 2.50 DC or greater is of particular clinical concern, as amblyopia risk is highest and treatment least effective once the critical period of visual development has closed. [6] A Pakistani nationwide study found that approximately one in five high school students carries a visually disabling refractive error without correction, a sign that early detection efforts are not reaching this population. [7] Genetic factors play a bigger role in astigmatism severity than clinicians often appreciate. Twin studies, sibling and parent-offspring analyses, and molecular genome-wide association studies converge on this conclusion. A 2024 meta-analysis in the American Journal of Ophthalmology, synthesizing 47 heritability studies, reported pooled heritability estimates of 0.46 for refractive astigmatism, 0.48 for corneal astigmatism, and 0.64 for corneal curvature, indicating that genetic factors account for nearly half to nearly two-thirds of the variation in a