Myopic hydrogen keratophakia offers several potential advantages over existing forms of corneal refractive surgery. Because no tissue lathing is required, neither donor tissue nor complex lathing equipment is necessary. Theoretically, hydrogen lens implants with precisely determined and verifiable parameters can be obtained in limitless supply. The surgical effect can be either modified or reversed, if clinically indicated. In this preliminary report, myopic hydrogel implants, with powers between -5 diopters and -20 diopters, were placed in nonhuman primate corneas. Corneascopic analysis showed significant flattening in all instances, and about 70%2of the anticipated correction was actually observed. Operative complications were infrequent and generally resulted from traumatic wound dehiscence. Myopic hydrogel keratophakia has tremendous clinical potential, but requires further experimental testing as to safety and efficacy.