早在四百年前,眼就被想象为小型相机,人眼的构造也确实颇似照相机(见图1):球壁外层的巩膜是眼球坚韧的外壳;中层的脉络膜含有很多色素细胞,具有阻止弥漫性光线从巩膜进入眼内的作用,给限内造成暗室情况,如同相机的暗箱;而虹膜中央的瞳孔,可以缩小和开大,控制进入眼内的光量,又似相机的光圈;眼内壁的视网膜是透明的可以感光的组织,起感光作用,好比胶片为外界物像的接受幕。眼的角膜、房水、晶状体、玻璃体是具有折光能力的透明介质,其弯曲面实与凸透镜的光学作用相同,故从光学角度来看乃是一系列透镜所组成的共轴球面系统。外界物体反射出的光线依次经过限内这组透镜——类似相机的镜头——发 As early as four hundred years ago, the eye was conceived as a small camera, and the human eye was indeed constructed like a camera (see Figure 1): the outer sclera of the wall of the ball is a tough envelope of the eyeball; the middle choroid contains many pigment cells, Has the function of stopping diffuse light from entering into the eye from the sclera and causing the dark room within the limit, like the camera’s black box; and the iris central pupil can be reduced and opened large, controlling the amount of light entering the eye and resembling the aperture of the camera; The retina of the inner wall of the eye is a transparent, light-sensitive tissue that functions as a light-sensitive film, like a film that receives the image of the outside world. The cornea of ​​the eye, aqueous humor, lens, vitreous body is a transparent medium with refractive power, and its curved surface is really the same as that of the convex lens. Therefore, from the optical point of view, it is a series of coaxial spherical systems composed of lenses. The light reflected by the outside world in turn passes through the lens of this group of lenses - similar to the camera - hair