cryopexy to treat retinal detachment. In 1964, he applied for a research grant from the John A. Hartford Foundation to further investigate freezing techniques in eye surgery and, in an addendum to the application, proposed "a method for removing a cataract through an incision small enough so that no hospitalization will be required." He received a three-year grant from the foundation. The idea for his next invention came to Kelman after seeing an ultrasonic device at his dentist's office. Kelman envisioned using a similar device that vibrates to break up a cataractous lens and remove it without a large incision. Kelman named the procedure phacoemulsification, a technique that has become standard treatment for cataracts. With medical instrument manufacturer Cavitron (which was later acquired by Coopervision), he devised an ultrasonic surgical instrument with an aspiration and irrigation system. He began testing the procedure on animals in April 1966. In 1967, Kelman secretly conducted his first surgery on a blind patient, awaiting enucleation, who volunteered knowing that the procedure would not bring back his vision. His first patient's eye became infected and was removed. However, he was successful on subsequent attempts. He had made further improvements on the instrument, increasing the vibration speed from 20,000 cycles per second to 40,000 cycles per second and creating a smaller hand instrument. On July 25, 1967, Kelman and his co-inventor Anton Banko filed a patent application to register a phacoemulsification device for cataract surgery. Kelman began a novel business relationship with the manufacturer to produce the device. After publishing "Phaco-emulsification and Aspiration—A New Technique for Cataract Removal: A Preliminary Report" in the American Journal of Ophthalmology, he began teaching courses to surgeons interested in learning this new technique. One of his students was Eric Arnott, a British ophthalmologist who introduced the procedure to the UK. Kelman's developments allowed the incision necessary for ECCE to be reduced from to and minimized recovery time. This new surgery method removed the need for an extended hospital stay and made the surgery less painful. The technique and similar tools have also been adopted and used in neurosurgery to remove tumors from the brain and spinal cord, and subsequently ushered a trend of minimally-invasive outpatient surgical procedures. Phacoemulsification initially faced significant criticism and skepticism in the 1970s. The National Eye Institute labeled the procedure as experimental, allowing insurance companies not to cover the procedure. Kelman's critics said the procedure was