Bifocal Spectacles vs. Single Vision Spectacles for Esotropia Greater at Near

Inclusion Criteria: * Age 3 to \<9 years * Esodeviation meeting all the following criteria is present in refractive correction (if required or worn) * Constant or intermittent esotropia ≥10∆ measurable by SPCT at near * Distance esotropia (constant, intermittent), esophoria, or orthophoria, with near esodeviation ≥10∆ larger than distance deviation by PACT * If constant ET at distance, then must be ≤6∆ by SPCT * If intermittent ET or esophoric at distance, can be any magnitude at distance (as long as near esodeviation is ≥10∆ larger than distance deviation by PACT) * Cycloplegic refraction within past 3 months (but not on day of exam) * Wearing spectacles for at least 4 weeks if refractive error is 0.75 D SE or more * Spectacles (if worn) must meet the following criteria: * SE refractive error must be corrected within ±0.625 D * Sphere power must be corrected within ±0.50 D * Anisometropia must be corrected within ±0.50 D SE * Cylinder power must be corrected within ±0.50 D * Cylinder axis must be within ±10 degrees if cylinder power is ≤1.00 D and within ±5 degrees if cylinder power is \>1.00 D. * Best-corrected VA meeting the following criteria: * Better-seeing eye VA is age-normal (see section 2.2) * IOD in VA within 0.2 logMAR (although previous amblyopia is allowed) * Worse-seeing eye VA of 20/63 or better * Investigator and parent willing to forgo treatment of ET other than assigned randomized treatment for 36 months unless failure crite…