Strasburger Hans, Bach Michael, Heinrich Sven P
Institute of Medical Psychology, Ludwig-Maximilians-Universität, München, Germany; Department of Medical Psychology and Medical Sociology, Georg-August University, Göttingen, Germany.
Section for Functional Vision Research, Eye Center at Medical Center, University of Freiburg, Freiburg im Breisgau, Germany; Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany.
Iperception. 2018 Apr 18;9(2):2041669518765850. doi: 10.1177/2041669518765850. eCollection 2018 Mar-Apr.
Optical blur from defocus is quite frequently considered as equivalent to low-pass filtering. Yet that belief, although not entirely wrong, is inaccurate. Here, we wish to disentangle the concepts of blur, caused by myopia or mis-accommodation, from blur due to low-pass filtering when convolving with a Gaussian kernel. Perhaps surprisingly-if well known in optometry-the representation of a blur kernel (or point-spread function) for dioptric blur is, to a good approximation and disregarding diffraction, simply a cylinder. Its projection onto the retina is classically referred to as a , the diameter of which can easily be deduced from a light-ray model. We further give the derivation of the relationship between the blur-disk's diameter and the extent of blur in diopters, as well as the diameter's relation to the near or far point, and finally its relationship to visual acuity.
离焦引起的光学模糊常常被认为等同于低通滤波。然而，这种观点虽不完全错误，但并不准确。在此，我们希望在与高斯核卷积时，将由近视或调节异常引起的模糊概念与低通滤波导致的模糊概念区分开来。也许令人惊讶的是——尽管在验光领域广为人知——屈光性模糊的模糊核（或点扩散函数）的表示，在很好的近似且忽略衍射的情况下，简单来说就是一个圆柱体。它在视网膜上的投影传统上被称为一个[此处原文缺失相关内容]，其直径可以很容易地从光线模型中推导出来。我们还给出了模糊盘直径与屈光度模糊程度之间关系的推导，以及直径与近点或远点的关系，最后是它与视力的关系。
