The principal purposes of corneal transplantation in patients with keratoconus are to improve visual function and reduce disability. In this study, 86% of grafts for keratoconus were performed to improve vision, of which BCVA is one measure. Visual acuity is difficult to standardize in community practice. Even when meticulously measured, BCVA may not be relevant to the daily functioning of the patient. A contact lens may be tolerated for the short time while BCVA is measured, but the patient, especially one with keratoconus, may not be prepared to use the lens with optimal refractive correction at other times. However, despite its limitations, BCVA is adequate to confirm the improvement in vision after penetrating keratoplasty for keratoconus. At the most recent follow-up, a BCVA of 20/40 or better was achieved by 74% compared with 8% preoperatively. However, for eyes with a preoperative BCVA of 20/20 or better, only 11% showed improved BCVA at the last follow-up, possibly because of regression to the mean.27 Patients with good preoperative BCVA, although less likely to achieve better BCVA postoperatively, may accept a reduction in BCVA as an alternative to wearing a contact lens. Overall, a higher proportion of eyes grafted for keratoconus exhibited a BCVA of 20/40 or better compared with all penetrating grafts, but this gain was achieved at the expense of a greater need for refractive aids and with significantly worse major astigmatism. Astigmatism is a particular problem with grafts for keratoconus26 and may be a cause of late graft failure.28 In patients with keratoconus, visual acuity may take several years to stabilize after graft9; in this study, relatively stable visual acuity was not observed until about 5 years after transplantation.