Improvements in capturing an image of a cornea with Placido's disk lines is disclosed. The imaging is with a clam shell clamping device that is easily clamped onto a cellular device and the lighting tube is centered on the camera so the image at the end of the tube can be captured. The clamping device includes a ring light source that illuminates the outside of the tube. The tube has a plurality of geometrically spaced light and dark rings to create evenly spaced rings on the cornea. Imperfections in the cornea will distort the rings. The camera can capture the image and the image or picture can be forwarded to a doctor or other care giver to determine the perfection or imperfection of the cornea.