Optical and imaging properties of a novel multi‐segment spectacle lens designed to slow myopia progression

Abstract Purpose High sampling density optical metrology combined with pupil‐ and image‐plane numerical analyses were applied to evaluate a novel spectacle lens containing multiple small zones designed to slow myopia progression. Methods High‐resolution aberrometry (ClearWave, www.lumetrics.com ) was used to sample wavefront slopes of a novel spectacle lens, Defocus Incorporated Multiple Segments (DIMS) ( www.hoya.com ), incorporating many small, positive‐powered lenslets in its periphery. Using wavefront slope and error maps, custom MATLAB software (‘Indiana Wavefront Analyzer’) was used to compute image‐plane point‐spread functions (PSF), modulation transfer functions (MTF), simulated images and power distributions created by the dual‐focus optic for different pupil sizes and target vergences. Results Outside of a central 10 mm zone containing single distance optical power, a hexagonal array of small 1 mm lenslets with nearest‐neighbour separations of 0.5 mm were distributed over the lens periphery. Sagittal and curvature‐based measures of optical power imperfectly captured the consistent +3.50 D add produced by the lenslets. Image plane simulations revealed multiple PSFs and poor image quality at the lenslet focal plane. Blur at the distance optic focal plane was consistent with a combination of diffraction blur from the distance optic and the approximately +3.50 D of defocus from the 1 mm diameter near optic zones. Conclusion Converging the defocused beams generated by the multiple small (1 mm diameter) lenslets to a blurred image at the distance focal plane produced a blur magnitude determined by the small lenslet diameter and not the overall pupil diameter. The distance optic located in between the near‐add lenslets determines the limits of the optical quality achievable by the lens. When compared to the optics of a traditional concentric‐zone dual‐focus contact lens, the optics of the DIMS lens generates higher‐contrast images at low spatial frequencies (<7 cycles per degree), but lower‐contrast at high spatial frequencies.