Abstract: A disposable bipolar instrument for ophthalmic surgery has a pair of shell halves carrying electrodes. A collar connects the shell halves together, and electrical conductors supply current to and from the respective electrodes. The shell halves are composed of disposable plastic material, as is the connecting collar and cap which connect the parts and hold the wires in place. Squeezing of the shell halves together is guided by a tongue-and-groove type of joint formed between the shell halves by pairs of upstanding walls, the walls having sloped surfaces in respective facing regions to permit deformation of the shell halves together at one end thereof, so as to permit movement of the electorde tips together to perform cauterization. The deformation of the plastic material causes a progressive resistance, thereby permitting a tactile feedback to the user, so that the instrument can be operated where the field of vision of the user is partially or totally obstructed.