Clinical comparison of the TruVision Omni and four progressive addition lenses.

The TruVision Omni is a progressive addition lens (PAL) using a bipolar design and the Dirichlet principle to minimize optical aberrations. The design was evaluated by having each patient elect to keep one lens type after masked paired comparison of the TruVision Omni with one of four other PAL types: VIP, Varilux, New Super NoLine, and Gradal HS. The Omni was chosen most frequently in each case: 16 to 8, 17 to 6, 18 to 6, and 15 to 3, respectively. Thirty-seven percent reported that no adaptation was required with the Omni compared to 20% for the paired PAL. In terms of specific performances, Omni tended to rank highest for intermediate distance functions and freedom from distortion, average for distance functions, and slightly above average for near function. The data support the merit of Omni's design strategy.