Purpose. To determine the benefit of bilateral penetrating keratoplasty wit
h regard to binocular vision. Methods. We compared patients who underwent c
orneal transplantation bilaterally with patients who had successful corneal
transplantation in one eye and corneal disease in the other eye. Specifica
lly, changes in fusion, stereopsis, and binocular vision function were anal
yzed. A questionnaire regarding performance of daily tasks was given. Resul
ts. Patients with bilateral keratoplasty performed better in all the analyz
ed functions. Fusion was achieved by 81.25% in the unilateral group versus
100% in the bilateral group (p = 0.15). Stereopsis was present more in the
bilateral group (100% vs. 62.5%, p = 0.008) and the quantity of stereopsis
was significantly better in the bilateral group (121 seconds of are vs. 1,2
84 seconds of are, p = 0.014). 88.8% of the patients subjectively improved
in daily activities after second eye surgery. Conclusion. There are objecti
ve and subjective improvements after bilateral penetrating keratoplasty.