This report of 300 cases of cataract extraction, from the Ophthalmologic Clinic of the University of Michigan, is offered primarily as a study of the comparative results obtained in three series of 100 consecutive cases in which operation was performed respectively by the combined, the simple and the Knapp-Torok methods of procedure. As a matter of record, there is included a table showing the incidence of the following complications: loss of vitreous, spontaneous hemorrhage, iris prolapse, infection, secondary glaucoma, average astigmatism and cataract delirium. Cases in which iridectomy had been performed previously, either as a preliminary to extraction or for the relief of glaucoma, are omitted from the series. The compilation of the visual results obtained after the cataract operation is usually made after one of two procedures has been followed. Either the percentage of the total number operated with a visual acuity of 6/12 or better is reported, or