A comparative evaluation of Readables to single vision lenses.

Emmetropic presbyopes are often prescribed single vision lenses for near or intermediate work. These lenses limit the usable range of clear vision especially in advanced presbyopia. Readables, a special purpose PAL that emphasizes intermediate and near vision extends the usable range by providing appropriately changing power over the middle 28 millimeters of the lens. A crossover design, randomized controlled clinical trial was undertaken to determine if Readables were perceived to provide better function than the single vision reading lens. Readables were preferred by a ratio of 25:2 and scored significantly better in lens performance measures. The design benefits of Readables are appreciated by the presbyopic patient.