Abstract
Purpose:
To determine the optimal design of pinhole contact lenses (PCL) without refractive power to obtain a full range of vision from far to near using a visual simulation system and to evaluate the optical performance.
Methods:
The PCL has a central clear zone in a 6.0-mm diameter opaque zone with many minute clear zones. The total diameter and the base curve of the PCL were 14.0 mm and 8.5 mm, respectively. The visual simulation system consists of a model eye and a charge-coupled device camera. The different PCLs can be placed in front of the model eye and evaluated. Visual simulations were performed using this system at 5, 1, and 0.3 meters through a 3-mm aperture using Landolt visual acuity (VA) charts with different PCLs (different sized central clear zone, 2.0, 1.8, 1.6, 1.4, and 1.2 mm; different sized minute clear zones in the opaque zone, 0.14, 0.17, 0.20, and 0.23 mm). The contrast levels of the gaps of the Landolt VA charts in the simulated images were analyzed using Photoshop software to determine the optimal PCL design.
Results:
The PCL with a 1.4-mm central clear zone and 0.17-mm clear zones in the opaque zone maintained the contrast of the simulated images over 10% at all distances and had the best performance among the tested designs.
Conclusions:
Our results suggested that the PCL without refractive power might be useful to obtain a full range of vision from far to near if designed optimally.
Keywords: 477 contact lens •
653 presbyopia •
676 refraction