PURPOSE: We report visual acuity improvement and refractive profiles in children prescribed glasses by a school-based vision program (SBVP) in Baltimore, Maryland. METHODS: In this cross-sectional analysis, pre-kindergarten through 8th grade students who failed vision screening underwent an eye examination. Students prescribed glasses are included. Visual acuity improvement was the difference between presenting and best-corrected visual acuity based on noncycloplegic manifest refraction. Clinically significant refractive error (CSRE) was defined as ≥0.75 D myopia, ≥2.00 D hyperopia without strabismus, ≥1.00 D hyperopia with esodeviation, or ≥1.50 D astigmatism AND presenting visual acuity ≤20/40 or ≥2-line difference with the better-seeing eye ≤20/30. Characteristics associated with greater visual acuity improvement were explored. RESULTS: Of the 4,972 students, mean age was 9.4 ± 2.7 years; 77% were black, and 18% were Hispanic. Myopia, hyperopia, astigmatism, and CSRE were found in 65%, 24%, 60%, and 46% students, respectively. In the better-seeing eyes, 70% gained ≥2 lines. Of students with CSRE, improvement of at least 5 lines in the worse-seeing eye increased from 30.9% in pre-kindergarten and kindergarten to 77.3% in 7th and 8th grade (Ptrend < 0.001). Students with CSRE had a higher rate of gaining at least 2 lines' improvement in their worse-seeing eyes compared with those without (98.7% vs 80.6%). Older students as well as blacks and Hispanics were more likely to have improvement of at least 2 lines. CONCLUSIONS: Most students prescribed glasses from our SBVP had clinically significant visual deficits corrected.