Which Pupul Size is Optimum?

Reading Test Small pupils have been employed as near reading aids for presbyopic eyes. However, will the benefits of small pupils present at high light levels still be retained at low light levels? What are the optimum pupil sizes for presbyopic eyes? We found that there is no fixed pupil size that is optimum for all light levels and defocus levels. However, a fixed 2-3mm small pupil or a 60-70% reduction of the pupil can both produce useful improvements in near visual acuity, image quality and reading performance without significant losses to distance visual acuity, for light levels ≥ 2cd/m2, which is the lowest text light levels we observed in a survey of internal environments.