Behavioral vision training for myopia: stimulus specificity of training effects.

The present study assessed transfer of visual training effects for myopia using two different training stimuli and a single subject A-B-C-A design. A male student volunteer, with lens prescription of -3.0 D (left) and -2.0 D (right), served as the subject. During baseline (10 sessions), visual acuity was assessed by two behavioral acuity tests. One test consisted of 50 line drawings of common objects as testing stimuli and the other test had 50 Chinese characters. A procedure including stimulus fading and reinforcement (positive verbal feedback) was used to train the subject to identify either pictorial stimuli or Chinese characters presented from a distance. Training was effective in improving performance on both behavioral acuity tests during the training phases and follow-up but the change was more pronounced on the specific stimuli being used for training. Refractive errors assessed on a weekly basis showed no change in the physiology of both eyes. These results suggest that effects of visual training only partially transferred to untrained stimuli.