Our lab studies what the eye tells the brain. We explore the structure and function of ganglion cells, the retinal neurons that communicate directly with the visual centers of the brain. There are more than a dozen types of ganglion cells. Each has anatomical and physiological features matched to the requirements of specific visual behaviors. We recently discovered a bizarre new type of ganglion cell that is a true photoreceptor, responding directly to light like a rod or cone. These cells synchronize the biological clock and constrict the pupil. Nearly all of our current work is devoted to understanding how these cells work and how their signals are used by the brain.