Abstract: The first step for removal of cataracts generally is a capsulotomy—the removal of the anterior capsule of the eye lens. The circular capsulotomy incision tool provides a device that produces sharper cuts, with precise measurements, in an economical, reliable form without the need for complicated or expensive equipment, or extensive surgeon training or skill. The tool uses a resilient ring with a sharp cutting edge. The ring is collapsed, put in place through a corneal incision, and the original circular shape is allowed to return. The device uses a pulley mechanism to rotate the ring, enabling the cutting edge to reliably create a precisely edged capsulotomy.