Accommodative relaxation by extending the viewing distance through the simple optical design of a double-mirror system

Abstract

This paper discusses the accommodative relaxation of myopic adults by using a simple double-mirror design. This optical design can extend the viewing distance to 2.285 m and magnify the image up to 3.79 times, and it results in the accommodative relaxation of a single human eye. We recruited 32 subjects with an average age of 20.8 ± 0.95 years old. After an examination of their refractive status, the disposable contact lenses with a corresponding refractive error were corrected, and the dynamic accommodative response and the change in pupil size were measured by using an open-field auto-refractor. The dynamic accommodative responses and pupil size data were collected under two viewing distance conditions. When the subjects gazed at a real object that was 0.4 m away, or a virtual image that was 2.285 m away, the mean value of the accommodative response was 1.69 ± 0.31D or 0.11 ± 0.05D, and the pupil size was 3.79 ± 0.49 mm or 4.09 ± 0.72 mm, respectively. The accommodative response decreased and the pupil size increased by using the double-mirror system, and therefore, accommodative relaxation can be achieved by using this new optical design. In this study, we first successfully proposed a simple optical design to relax the accommodation, and the fluctuations of the accommodation response were stable, with the extended viewing distance of 2.285 m. This design may be applied for the improvement of visual function, such as the reduction of asthenopia and the control of myopia.