It is the prime purpose of this communication to emphasize, on the basis of clinical experience, the very great importance of the use of digital pressure as a safeguard against vitreous loss in cataract surgery. Secondly, preliminary evidence is presented as to the mechanism of action of digital pressure in the production of this clinically observed increased safety. The first reference to the use of digital pressure following retrobulbar injection in intraocular surgery was by Atkinson1 in 1934, who stated: For a few moments slight pressure is exerted on the globe with a little rotary motion, so that the procaine solution is more thoroughly diffused within the muscular cone. Our interest in this problem began when one of us (R. E. K.) visited in Boston and observed the routine use by Chandler of five minutes of pressure following the retrobulbar injection. Chandler * wrote: "I hit upon the idea of