Effects of Stulln and Accommodative Training

The present study tests the hypothesis that Stulln eyedrops improve accommodative functions by improving the short term facility of ciliary muscles that can be transferred into long-term adaptation. To test this, the investigators propose to conduct a prospective randomized control trials where participants with accommodative dysfunctions are randomly assigned to four groups: control, Stulln only and Stulln plus vision training. The investigators' theory predicts that the efficacy of Stulln will be augmented by vision training.