De Lestrange-Anginieur E, Kee C S
School of Optometry, Hong Kong Polytechnic University, Hong Kong.
Interdisciplinary Division of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong SAR, China.
Heliyon. 2020 Jul 23;6(7):e04153. doi: 10.1016/j.heliyon.2020.e04153. eCollection 2020 Jul.
Although it is possible to specify the impact of blur at a specific retinal location, a lack of understanding exists regarding how the inhomogeneous blur distribution across the retina (i.e., global blur) affects the quality of an optical correction at a specific retinal location. To elucidate this issue, a multiscale visual simulator combining the projection of a controllable high-resolution stimulus and an ocular monitoring system was constructed to simultaneously simulate foveal and extrafoveal blurs. To define the range and capability of a wide-angle stimulation, an optimal working pupil was evaluated by optical ray-tracing via a Monte Carlo simulation, including optical variations corresponding to fixational eye movements. To investigate the impacts of global blur on the perception of discrete regions of the visual field, the bothersome blur threshold from five subjects was measured through this novel system using a collection of zonal blurs (annuli image projected sequentially at discrete retinal regions), and these impacts were compared with those using a spatially-varying blur (continuum of simultaneously projected zonal blurs of varying strengths, simulating retinal blur variations). Our results show that the zonal blur threshold does not entirely predict the global blur threshold, having a tendency to overestimate blur the threshold. It was concluded that, in addition to the amount of defocus present at a defined retinal location, the perception of individual defocused retinal regions can be affected by global blur. Given that blur tolerance can affect the perception of optically induced blurs, the findings provide useful implications for designing new optical correction.
虽然可以确定特定视网膜位置的模糊影响，但对于视网膜上不均匀的模糊分布（即整体模糊）如何影响特定视网膜位置的光学矫正质量，人们尚缺乏了解。为阐明这一问题，构建了一个多尺度视觉模拟器，它结合了可控高分辨率刺激的投影和眼部监测系统，以同时模拟中央凹和中央凹外的模糊。为确定广角刺激的范围和能力，通过蒙特卡洛模拟的光线追踪评估了最佳工作瞳孔，包括与注视眼动对应的光学变化。为研究整体模糊对视野离散区域感知的影响，使用该新型系统，通过一系列区域模糊（在离散视网膜区域依次投影的环形图像）测量了五名受试者的令人烦恼的模糊阈值，并将这些影响与使用空间变化模糊（同时投影不同强度的区域模糊连续体，模拟视网膜模糊变化）的情况进行了比较。我们的结果表明，区域模糊阈值不能完全预测整体模糊阈值，有高估模糊阈值的趋势。得出的结论是，除了在定义的视网膜位置存在的散焦量外，各个散焦视网膜区域的感知还会受到整体模糊的影响。鉴于模糊耐受性会影响对光学诱导模糊的感知，这些发现为设计新的光学矫正提供了有用的启示。
