Contrast sensitivity was measured using the CSV-1000 HGT testing instrument (Vector Vision Inc.), which presents a translucent chart divided into 4 cycles with spatial frequencies of 3, 6, 12, and 18 cycles per degree (cpd). The background illumination of the translucent chart does not depend on room lighting; rather, it is provided by a fluorescent luminance source of the instrument and is automatically calibrated to 85 candelas/m2. All measurements were obtained under mesopic (5 cd/m2) and photopic (85 cd/m2) conditions. Each cycle contains 17 round patches that are 1.5 inches in diameter. The first patch has a high-contrast grating and presents the sample. The test patches are arranged in 2 rows with 8 levels of contrast. The levels decreased from left to right along the row in a logarithmic fashion in 0.17 log units for steps 1 through 3 and 0.15 log units for steps 3 through 8. The examinations were performed unilaterally at a distance of 2.5 m with best corrected visual acuity (BCVA) and an undilated pupil. All measurements were conducted under the same conditions by an examiner who was unaware of the type of IOL implanted.