To evaluate the effect of the EYEPORT II vision training system (Bernell) on accommodation in cases of accommodative insufficiency. The experimental study was conducted in a binocular vision clinic. Of 230 patients, 36 were eligible and willing to participate in office-based therapy. Participants were randomly divided into two groups: control and EYEPORT. The control group received conventional therapy and the EYEPORT group received conventional therapy combined with the EYEPORT II vision training device. The therapy lasted for 1 hour daily over 6 days in a week, with 24 sessions administered over 4 weeks. Accommodative parameters were reevaluated 2 weeks, 4 weeks, and 24 months after treatment. The study included 19 men and 17 women, with a median age of 27.50 years. After 24 sessions of vision therapy, accommodative parameters improved significantly, with more pronounced results compared with baseline measurements, as demonstrated by the Wilcoxon signed-rank test (P < .05). The Mann-Whitney U test indicated a significant (P < .05) improvement in treatment outcomes for the EYEPORT group using the EYEPORT device together with conventional therapy. The median accommodation amplitude increased by 6.95 diopters (D), the accommodation lag decreased by -0.25 D, the positive relative accommodation improved by -1.63 D, and the accommodative facility increased by 13 cycles/minute. After 3 months without therapy, the treatment outcome was maintained. Office-based vision therapy can effectively treat accommodative insufficiency. Both groups showed improvement in the accommodative amplitude and other parameters. The EYEPORT group was more stable at 3 months. [J Pediatr Ophthalmol Strabismus. 20XX;XX(X):XXX-XXX.].