It turns out that the cornea of an eye and a camera viewing the eye form a catadioptric (lens + mirror) imaging system, which we refer to as a corneal imaging system. Unlike a typical catadioptric imaging system, a corneal one is flexible in that the reflector (cornea) is not rigidly attached to the camera. Using a geometric model of the cornea based on anatomical studies, its 3D location and orientation can be estimated from a single image of the eye. Once this is done, a wide-angle view of the environment of the person can be obtained from the image. In addition, we can compute the projection of the environment onto the retina with its center aligned with the gaze direction. This foveated retinal image reveals what the person is looking at.