Spectacle Prescribing in Early Childhood

Inclusion Criteria: * Parent/guardian provision of signed and dated informed consent form for Baseline/Eligibility Examination. * Completion of Baseline/Eligibility Examination with cycloplegia. * Bilateral astigmatism: Astigmatism ≥2.25D in the most astigmatic eye and ≥1.75D in the fellow eye based on manual cycloplegic retinoscopy conducted at Baseline/Eligibility Examination. * Parent/guardian willing to accept assignment to either randomized group. * Parent/guardian provision of signed and dated informed consent form for randomized SPEC Study. * Parent willing to commit to study visits every 180 days, to be contacted (phone, email, or text) for reports of spectacle wear, and to allow their child to wear the TheraMon® sensor on the spectacle headband. * Child and Family are primarily English or Spanish speaking. * Parent/guardian does not anticipate moving out of Tucson area prior to their child reaching age 1275 days (approximately age 3 ½ years). * Parent/guardian has not enrolled another child in the SPEC trial. Exclusion Criteria: * Gestational age \<32 weeks (per parent report). * Anisometropia ≥1.50 D spherical equivalent per manual cycloplegic retinoscopy conducted at the Baseline/Eligibility Examination. * Current manifest strabismus per Baseline/Eligibility Examination. * Ocular pathology per Baseline/Eligibility Examination (H44\* or H25\* diagnosis code). * Previously diagnosed manifest strabismus or other ocular abnormalities (per parent report and per medic…