Devices and methods are disclosed for improved irrigation sleeves for ophthalmic instruments to prevent or reduce the likelihood of the irrigation sleeve twisting and/or buckling upon inserting the irrigation sleeve into the eye. In some embodiments, an irrigation sleeve comprises a side opening for irrigation having an elongated shape, wherein the elongated shape is longer in a direction parallel to the longitudinal axis of the distal tube of the irrigation sleeve than in a direction around a circumference of the distal tube of the irrigation sleeve. In some embodiments, an irrigation sleeve comprises at least one rib on an internal surface of the distal end of the irrigation sleeve. In some embodiments, the irrigation sleeve has been subjected to one or more manufacturing steps adapted to stiffen the irrigation sleeve, such as being coated with a stiffening coating or being treated by being exposed to gamma irradiation.