Purpose: To evaluate the visual outcomes of full refractive correction as a standalone initial treatment for anisometropic amblyopia in children aged 5 to 15 years and to identify predictive factors for treatment success. Methods: This longitudinal cohort study included 128 children (mean age 9.8 ± 3.2 years) with previously untreated anisometropic amblyopia. All participants received full-time spectacle correction based on their full cycloplegic refraction. The primary outcome measure was the improvement in best-corrected visual acuity (BCVA) in the amblyopic eye, measured in LogMAR units. Treatment was considered successful if the inter-ocular acuity difference was reduced to 0.2 LogMAR units (2 lines) or less. Follow-up examinations were conducted at 3, 6, 12, and 24 months. Results: After 12 months, 78 of 128 participants (60.9%) achieved successful visual outcomes with spectacle correction alone. The mean BCVA in the amblyopic eyes improved significantly from a baseline of 0.78 ± 0.25 LogMAR to 0.35 ± 0.21 LogMAR. Children in the younger cohort (5 to <10 years) demonstrated a higher success rate (71.2%) compared to the older cohort (10 to 15 years) (48.3%, p < 0.01). Logistic regression analysis identified the initial degree of anisometropia as the strongest predictor of treatment failure, with each additional diopter of anisometropia increasing the odds of an unsuccessful outcome. The type of refractive error (myopic vs. hyperopic) was not found to be a statistically significant predictor. Conclusion: Full refractive correction serves as an effective primary intervention for a majority of children with anisometropic amblyopia, including those up to 15 years of age. While younger age is associated with better outcomes, substantial visual improvement can still be achieved in older children. The initial magnitude of anisometropia is a critical factor for prognosticating treatment success and may help identify patients who will likely require earlier adjunctive therapy, such as occlusion or atropine penalization.