Background: A camera-based microswitch technology was recently developed to monitor small facial responses of persons with multiple disabilities and allow those responses to control environmental stimulation. This study assessed such a technology with 2 new participants using slight variations of previous responses. Method: The technology involved a computer with a CPU using a 2GHz clock, a USB video camera with 16-mm lens, and special software. Small colour spots were used under the lower lip of one participant and on the eyelid of the other participant to aid the camera and computer to detect their mouth and eyelid responses. The study involved an ABAB design and included a 3-week post-intervention check. Results: The participants' mouth and eyelid responses increased during the intervention (B) phases and post-intervention check (i.e., when the technology allowed them to control stimulation). Conclusions: Camera-based microswitch technology can help persons with multiple disabilities control stimulation with small responses. (Contains 2 figures.)