Base-in Prism Spectacles for Intermittent Exotropia

Inclusion Criteria: Intermittent Exotropia meeting all of the following criteria: * Age 3 to 13 years * Mean distance control score of ≥2.00 points with at least 1 measure of 3, 4, or 5 points (i.e, spontaneous tropia) from the 3 assessments during the exam * A near control score ≤4 on at least 1 of 3 assessments (cannot have score of 5, 5, 5) * Distance exodeviation between 16 Prism Diopters (Δ) and 35 Δ (inclusive) by PACT * Near exodeviation between 10 Δ and 35 Δ (inclusive) by PACT * Near deviation does not exceed distance deviation by more than 10 Δ by PACT (i.e., convergence insufficiency-type IXT excluded) * Refractive error between -6.00 Diopters (D) spherical equivalent (SE) and +2.50 D SE (inclusive) (based on a cycloplegic refraction performed within 7 months but prior to the day of enrollment) * Refractive correction (must be worn for at least 1 week if refractive error meets any of the following (based on a cycloplegic refraction performed within 7 months but prior to the day of enrollment): * SE anisometropia ≥1.00 D * Astigmatism ≥1.00 D in either eye * SE myopia ≥-0.50 D in either eye * If spectacles have been prescribed and are worn, they must meet the following pre- enrollment criteria: * SE anisometropia corrected to within 1.00 D of full SE anisometropic difference * Astigmatism corrected to within 1.00 D of full magnitude; axis within 10 degrees if astigmatism ≤1.00 D and axis within 5 degrees if astigmatism \>1.00 D Exclusion Criteria: * …