Research scientists based at the University of California, Berkeley, the University of Bonn, Germany and the University of Alabama, Birmingham, have published research in which adaptive optics micro-stimulation and high speed eye tracking appeared capable of revealing certain retinal functions at the level of individual photoreceptors. The research paper, published in the Journal of Neuroscience (34(16): 5667-5677), demonstrated that vision could be detected on the perceptual level through the stimulation of a single photoreceptor. Facilitated by significant advances in ocular imaging in recent years, and combined with sophisticated real-time retinal tracking that can compensate for eye movement, the researchers were able to deliver stimulation to single cone photoreceptor cells. The research team behind the work suggests that such novel methodology to test function at the cellular level in the in vivo human retina may open new opportunities in both vision science and understanding of retinal disease.