Objective and subjective assessment of a new diffractive trifocal contact lens.

The purpose of this study was to test the objective and subjective performance of the Holo-Or Rigid Gas Permeable (RGP) Multifocal Contact Lens (MFCL), a new trifocal diffractive contact lens. Eleven experienced and two nonexperienced rigid gas permeable contact lens wearers participated in the study. Eleven patients were presbyopic (age 40-57) and two were aphakic (age 12 and 14). All patients were tested both with their best correction for distance and near and trifocal diffractive contact lenses. The follow-up period was 3-8 months. Subjective opinion was also assessed. Statistical analysis was performed using Student's t-test. We did not find any significant difference in visual acuity, measured at 6 m, 80 cm, and 40 cm, between best correction and Holo-Or diffractive contact lenses. Depth of focus improved to a statistically significant extent when using trifocal contact lenses. A small reduction in contrast sensitivity was observed when the patients used multifocal contact lenses. Overall satisfaction and comfort was good to excellent in 10 out of 13 patients. Two additional patients who used a bifocal model of the same contact lens design showed similar results. Holo-Or Trifocal Diffractive Contact Lenses are a satisfactory means of optical correction for patients with presbyopia or accommodative problems.