Purpose. Near esophoria has been linked to the onset and progression of myopia in children in two opposite ways: (1) esophoria is secondary to excessive accommodation at near which is thought to produce myopia, or (2) near esophoria leads to underaccommodation in order to maintain binocular fusion. The resulting blurred image produces myopia as in animal models. In order to differentiate between these competing hypotheses, we measured accommodation and phoric alignment in children with known refractive histories. Methods. Eighteen myopic and 44 emmetropic subjects, aged 7-21 yrs, were tested. Accommodation was measured for the right eye with an infrared autorefractor during monocular viewing of 20/100 letters at 4.0 m and 33 cm. Concomitant phorias were obtained with a Maddox rod and prism before the left eye. Results. Myopes who are esophoric accommodate significantly less to a near target than those who are exophoric (p<0.05). In the myopes, accommodation is significantly correlated with both near (r = -0.50, p<0.03) and distance phorias (r = -0.59, p<0.01). In the emmetropes, accommodation is significantly correlated with distance phoria (r = -0.38, p<0.01), but not near (r = -0.18, ns). Mean near phoria is 2 Δ exo for both refractive groups. Future measures will indicate whether emmetropes who become myopic are more esophoric than those who remain emmetropic. Conclusions. Progressing myopes with near esophoria tend to underaccommodate, lending support to the second hypothesis. Thus bifocal or progressive addition lenses, alleged to slow myopia progression, may accomplish this by eliminating the blur caused by underaccommodation rather than by reducing overaccommodation.