Abstract: The invention relates to an ophthalmic surgery instrument (1; 101) for making a substantially circular cut in an internal part (110) of an eye (109), in particular for capsulorhexis, comprising a handle (2; 102) at the end of which there extends a rod (3; 103) carrying a blade (4; 104) designed to be introduced into the eye (109) via an incision (107) that has been formed in the latter, characterized in that the blade (4; 104) has a loop shape with dimensions substantially equal to those of the cut, and the instrument comprises means for passing the blade through the incision.

Abstract: A microkeratome cutter head comprising a body and a cutter blade slidably mounted in a housing passing through the body in a direction substantially parallel to the cutting edge of the blade, wherein the blade possesses a slot parallel to its cutting edge and opening out into one of the side edges of the blade, while the housing possesses a partition received in the slot of the blade as it is inserted into the body, and co-operating with the edges of the slot to guide the blade in its motion parallel to its cutting edge.

Abstract: A cutter head for a microkeratome, the head including a guide housing for an alternating cutter blade having a cutting edge, a rear edge, and two side edges, the housing having two parallel pairs of faces that are spaced apart by a distance substantially equal to the thickness of the blade and that are situated respectively in the vicinity of the cutting edge and the vicinity of the rear edge of the blade, wherein each of the pairs of parallel faces is of a length measured parallel to the cutting edge that is shorter than the distance between the lateral edges of the blades in register therewith, minus the peak-to-peak amplitude of the reciprocating oscillation.