Cohen S Y
Clinique ophthalmologique universitaire, Centre hospitalier intercommunal, Créteil.
Rev Prat. 1993 Sep 15;43(14):1757-60.
The eye is a perceptive system with extremely complex physiology, although its optical properties can be assimilated to those of spherical diopters. Various approximations make it possible to reduce the eyeball to a single convex diopter. With a normal eye the image of an object situated ad infinitum focuses on the retina. The normal eye is called emmetropic. Otherwise, the eye is called ametropic. Several types of ametropy exist. When the image focuses in front of the retina the eye is said to be myopic. When the image focuses behind the retina the eye is called hypermetropic (or hyperopic). When the image of an object differs according to various focusing axes, the eye is said to be astigmatic.
眼睛是一个生理极其复杂的感知系统，尽管其光学特性可类比于球面屈光镜。通过各种近似方法，可以将眼球简化为一个单一的凸透镜。正常眼睛能将无限远处物体的图像聚焦在视网膜上。这种正常的眼睛被称为正视眼。否则，眼睛就被称为屈光不正。屈光不正有几种类型。当图像聚焦在视网膜前方时，眼睛被称为近视。当图像聚焦在视网膜后方时，眼睛被称为远视（或远视眼）。当物体的图像根据不同的聚焦轴而不同时，眼睛被称为散光。
