A 5-year-old girl with previously unrecognized hyperopia of approximately +3.00 D developed esotropia while being treated with oxybutynin for enuresis. The esotropia disappeared with cessation of oxybutynin and correction of her hyperopia. When the hyperopic correction was removed, she had a small esophoria. The esotropia was presumably triggered by the anticholinergic effect of oxybutynin, which reduced the ability to accommodate. The increased accommodative effort for vision generated an esotropia as a result of the accommodative convergence/accommodation ratio.