A biofeedback system and method enables biofeedback training to be accomplished during normal interaction by an individual with the individual's environment, for example while reading, playing video games, watching TV, participating in sports activities, or at work. Physiologic data is processed and used to generate one or more control signals based on the physiologic data. The control signals may be proportional to a result of the data processing, or based on comparison of the processing results with at least one fixed or adaptive threshold. The control signal is supplied to a wearable device through which the individual receives sensory information from the individual's environment, and serves to interrupt or modify the sensory information. The wearable device may be an eyeglass device including a dynamic lens display, with the control signal being supplied to the dynamic lens display to modulate visual information received through the eyeglass device by obscuring, distorting, or otherwise affecting the clarity of the visual information. Feedback may also be provided in the form of auditory or tactile feedback.