To report wavefront analysis of successful treatment of monocular triplopia after cataract extraction.

(Case 1) A 59-year-old man visited our clinic for a monocular triplopia in his left eye of five years in duration. The best spectacle-corrected visual acuity (BSCVA) was 1.0 in the left eye, and the patient had a mild cortical cataract. The ocular spherical aberration (0.126 µm for the 4-mm pupil, 0.351 µm for the 6-mm pupil) measured by a Hartmann-Shack aberrometer increased preoperatively, while the corneal spherical aberration was normal. After cataract surgery, the monocular triplopia disappeared, and the ocular spherical aberration decreased. (Case 2) A 38-year-old man visited our clinic for a monocular triplopia in his left eye of a two-year duration. The best spectacle-corrected visual acuity (BSCVA) was 0.3 in the left eye, and the patient had a mild nuclear cataract. The ocular spherical aberration (-0.356 µm, -1.343 µm) and trefoil aberration (0.199 µm, 0.252 µm) increased preoperatively, while the corneal spherical and trefoil aberrations were normal. After cataract surgery, the monocular triplopia disappeared and the ocular spherical and trefoil aberrations decreased.