To reveal refractive errors, the relationship between refractive errors and optical parameters, and the effect of prematurity and retinopathy of prematurity (ROP) on ocular development in school children with a history of prematurity. Premature children aged 8-12years were divided into 3 groups as those without ROP (Group 1), with ROP that did not require treatment (Group 2), and with laser-treated ROP (Group 3). Age-matched full-term healthy children were included in the control group. Demographic features were recorded. A detailed ophthalmologic examination was performed. Anterior chamber depth (ACD), trabecular-iris angle (TIA), iris thickness (IT), lens thickness (LT), vitreous body length (VBL),axial length (AL) were measured by ultrasound biomicroscopy (UBM). The results were compared between groups. Group 3 had the lowest best corrected visual acuity (0.81 ± 0.31 SL), the highest rates of myopia (55.9%) and astigmatism (50.0%). In the premature groups, ACD (p < 0.001), TIA (p < 0.001), IT (p = 0.016), VBL (p < 0.001) and AL (p < 0.001) were lower; LT (p < 0.001) was higher than in the control group. As birth weight (BW) and gestational age (GA) increased, ACD, TIA, VBL and AL increased, and LT decreased (p < 0.001). In the group 3, 35.2% anisometropia, 17.6% of esotropia and 5.9% of exotropia were detected. The frequency of myopia, astigmatism, hyperopia and anisometropia is increasing in premature children, especially in cases with laser-treated ROP. Premature cases are characterized by thicker lens, shallower ACD, narrower TIA and shorter AL. Refractive errors, anisometropia, amblyopia and strabismus are important causes of visual impairment in children with laser-treated ROP.