A device for cutting and aspirating tissue from the human or animal body, preferably for use in ophthalmology, particularly for vitrectomy, for retinal peeling, etc., with an outer tube (1), and with an inner tube (11), which can move to and fro concentrically in the outer tube (1) with slight play, wherein the outer tube (1) is closed at the free end (2), and has, near the free end (2), a first and a second lateral opening (3, 4) with in each case at least one inner cutting edge (7, 8), wherein the inner tube (11) is open at the free end and there has an outer cutting edge (12), wherein the inner tube (11) has, near the free end, at least one lateral opening (13) with at least one further outer cutting edge (14), and wherein the cutting edges (7, 8, 12, 14) of the outer tube (1) and of the inner tube (11) cooperate in a cutting action during the movement of the inner tube (11), characterized in that the first and second opening (3, 4) are each designed as an asymmetrical circle, as an asymmetrical circle, a an asymmetrical ellipse or as an asymmetrical oval, and in that a thin web (6) is formed by the asymmetrical area (5) of the first and second opening (3, 4) on the outer tube (1).