Roorda A, Campbell M C, Bobier W R
School of Optometry, University of Waterloo, Ontario, Canada.
J Opt Soc Am A Opt Image Sci Vis. 1995 Aug;12(8):1647-56. doi: 10.1364/josaa.12.001647.
In eccentric photorefraction, light returning from the retina of the eye is photographed by a camera focused on the eye's pupil. We use a geometrical model of eccentric photorefraction to generate intensity profiles across the pupil image. The intensity profiles for three different monochromatic aberration functions induced in a single eye are predicted and show good agreement with the measured eccentric photorefraction intensity profiles. A directional reflection from the retina is incorporated into the calculation. Intensity profiles for symmetric and asymmetric aberrations are generated and measured. The latter profile shows a dependency on the source position and the meridian. The magnitude of the effect of thresholding on measured pattern extents is predicted. Monochromatic aberrations in human eyes will cause deviations in the eccentric photorefraction measurements from traditional crescents caused by defocus and may cause misdiagnoses of ametropia or anisometropia. Our results suggest that measuring refraction along the vertical meridian is preferred for screening studies with the eccentric photorefractor.
在偏心摄影验光中，从眼睛视网膜返回的光由聚焦于眼睛瞳孔的相机进行拍摄。我们使用偏心摄影验光的几何模型来生成瞳孔图像上的强度分布。预测了单眼中诱导的三种不同单色像差函数的强度分布，并与测量的偏心摄影验光强度分布显示出良好的一致性。计算中纳入了来自视网膜的定向反射。生成并测量了对称和非对称像差的强度分布。后者的分布显示出对光源位置和子午线的依赖性。预测了阈值处理对测量图案范围的影响大小。人眼的单色像差会导致偏心摄影验光测量结果与由散焦引起的传统月牙形产生偏差，并可能导致屈光不正或屈光参差的误诊。我们的结果表明，对于使用偏心验光仪进行的筛查研究，沿垂直子午线测量屈光是首选。
