A two-dimensional mapping with a strange attractor

A surgical knife which is particularly adapted to achieve a more precise incision for cataract extractin includes a handle having at one end cutting means in the form of a projecting planar shoe member which is spaced from a pair of projecting ski members, and wherein the cutting blade is disposed perpendicular to the plane of the shoe member, and extends from said shoe member to the space between the ski members. In use, during a cataract operation, the shoe is introduced in the angle created by the iris and the cornea, and is operative to prevent the cutting means or razor blade which is attached perpendicularly to the shoe from encountering the iris and the lens. The spaced skis are positioned outside the eye so as to act as a guide and prevent the surgeon from inadvertently pushing the shoe into the iris or the lens.