Abstract: A cornea is altered in shape by providing a template body to guide a surgical blade, the body being formed in a semi-spherical hollow with the outer wall concentric with the inner surface of the cornea and the inner wall of the template body concentric with the outer surface of the cornea. The template body affords a rest surface for a shoulder on the surgical blade to limit penetration of the blade into the cornea in accordance with the thickness of the template body, which varies inversely with the thickness of the cornea to preclude blade penetration of the anterior chamber of the eye behind the cornea. Guide slits in various patterns are formed in the template body between the optic zone and the limbus circles diameter of the eye to change the resistance of the cornea to inner eye pressures and thus alter the corneal shape to correct focal problems of the eye.

Abstract: Novel tool operating apparatus is exemplified in a dental treatment device capable of driving alternatively at least a first tool and a second tool, each tool being intended to execute a different form of motion, with a single tool driving means to which each of several different tools can be removably coupled. The driving means includes a rotatable drive shaft fitted with tool engagement means in the form of a disc affixed to the shaft and lying in a plane that makes an acute angle with the rotational axis of the shaft. One tool can be fitted over the shaft to engage the disc so as to rotate the tool with the shaft. A second tool can be fitted over the shaft so that the shaft can rotate within the tool, but the tool will not rotate with the shaft. The second tool has means for cooperating with the shaft so as to execute an oscillatory motion relative to the shaft axis.

Abstract: Curvette of generally circular form having apertures adjacent the outer periphery and having a plurality of compartment elements formed of an optically-clear plastic snugly locked in the apertures.

Abstract: A slide filter for filtering plastic stock and other materials having a slide plate movable within a housing, across the path of material flow. The housing contains sealing means to prevent leakage of the material to the outside of the housing. The slide plate includes one or more recesses bounded by wall means within which a mechanical screen or sand pack filter is positioned.

Abstract: An extended-area filter for filtering plastic stock at high pressures has a breaker plate with an undulating surface confronting the oncoming stock which substantially doubles the available filter area. Screen packs having fixed therein the same surface configuration are supported uniformly on the undulating surface against collapse under the operating pressure.