Aspheric spectacles for correcting presbyopia with myopia and astigmatism.

The aim of this paper is to propose a method for designing aspheric spectacles capable of realizing good optical performance at both far and near vision for presbyopia. We have experimentally measured wavefront aberrations and axial lengths for eight myopic eyes. In consideration of the field of view (FOV), the rotation of the eyeball, and a small amount of accommodation retained for presbyopia, we constructed individual eye models and optimized all the spectacle-eye systems for visible wavelengths by Zemax's simulation. Finally, we evaluated the image quality by the modulation transfer function (MTF) and visual acuity (VA) with different pupil sizes (2, 2.8, 4 mm). Results show that when the pupil size is 2 mm or 2.8 mm, the spectacles designed for the full FOV (0° and ±4° FOV) provide a strong ability to transfer low contrast at both far and near vision, and the VA for all reaches 0.8, and up to 1.1 for eyes NO. 1, NO. 5, NO. 6, and NO. 8 for the 0° FOV. As the pupil size increases to 4 mm, the VA for all comes to 0.6 for the full FOV, indicating that presbyopia is able to acquire a good visual resolution at both far and near vision by the designed aspheric spectacles. Furthermore, we verified the visual continuity of the spectacle-eye systems by studying intermediate vision, which demonstrates that the method used in our design is accurate and practicable.