An eye-mountable device includes an image sensor situated in a polymeric material configured to be mounted to a surface of an eye. The image sensor can be disposed on a substrate at least partially embedded in the polymeric material. The image sensor can include a photo-sensitive area occupied by a plurality of photo-sensitive elements. The photo-sensitive area is illuminated by light entering a plurality of light channels. Each of the light channels has a respective orientation such that light passes through a given light channel from a respective direction. A given portion of the photo-sensitive elements therefore receives light from a respective direction corresponding to the one of the light channels that illuminates it. The direction-specific measurements of received light obtained by the multiple photo-sensitive elements can thereby be used to form an image.