目的:这项工作的目的是检查Seidel球面像差(SA)对最佳屈光状态的影响,以检测和区分黑暗背景上的小亮光。
方法:使用自适应光学系统校正环状眼睛的像差,然后系统地引入5个级别的SeidelSA,以获得7毫米直径的瞳孔:0,±0.18和±0.36屈光度(D)mm-2。对于每个级别的SA,受试者需要在黑暗背景上检测一个或解决两个光点(0.54弧分直径)。通过调整刺激聚散度以最小化检测和分辨率阈值来测量折射误差。对于单个光点的另外两个新颖的聚焦任务需要最大化亮点核心的感知强度并最小化其整体感知尺寸(即最小化星爆伪影)。除了探测任务,在低于0.5cdm-2的黑色背景下,光点的亮度为1000cdm-2。
结果:当没有SA时,阳性SA相对于明亮背景上的深色字母的最佳主观焦点引入了近视偏移,而负SA在最佳焦点中引入远视偏移。对于检测任务,每Dmm-2的SA,最佳焦距的变化分别为-1.7、-2.4、-2.0和-9.2D。解析任务,核强度的最大化和尺寸的最小化,分别。
结论:当观察夜间环境中通常遇到的高对比度点源时,眼SA可能是导致屈光状态变化的重要因素。
OBJECTIVE: The aim of this work was to examine the impact of Seidel spherical aberration (SA) on optimum refractive state for detecting and discriminating small bright lights on a dark background.
METHODS: An adaptive-optics system was used to correct ocular aberrations of cyclopleged eyes and then systematically introduce five levels of Seidel SA for a 7-mm diameter pupil: 0,±0.18, and±0.36diopters (D)mm-2. For each level of SA, subjects were required to detect one or resolve two points of light (0.54 arc min diameter) on a dark background. Refractive error was measured by adjusting stimulus vergence to minimize detection and resolution thresholds. Two other novel focusing tasks for single points of light required maximizing the perceived intensity of a bright point\'s core and minimizing its overall perceived size (i.e. minimize
starburst artifacts). Except for the detection task, luminance of the point of light was 1000cdm-2 on a black background lower than 0.5cdm-2.
RESULTS: Positive SA introduced myopic shifts relative to the best subjective focus for dark letters on a bright background when there was no SA, whereas negative SA introduced hyperopic shifts in optimal focus. The changes in optimal focus were -1.7, -2.4, -2.0, and -9.2D of focus per Dmm-2 of SA for the detection task, resolution task, and maximization of core\'s intensity and minimization of size, respectively.
CONCLUSIONS: Ocular SA can be a significant contributor to changes in refractive state when viewing high-contrast point sources typically encountered in nighttime environments.