人到中年以后,全身器官的形态和功能开始出现一些衰退的现象。眼睛也是如此,并表现得更加明显。一般说来,人一过40岁,眼睛的变化就会出现这样一些现象: 老花眼老视这是最普遍的现象。在正常的情况下,眼睛可以看清远处的景物,但是看清近处,就需要通过睫状肌的收缩来改变晶体的突出度,这就同摄影需要焦距一样。人到中年以后,晶体逐渐地发生硬化,弹性减退,睫状肌肌力降低,调节能力也就差了。此时,看近处的景物,特别是在光线不足的时候读书看报,觉得模模糊糊的,这就是老视。晶体混浊另一种普遍的现象是晶体开始发生混浊。白内障的形成因素尽管是多方面 After middle age, the appearance and function of the whole body organs begin to show some signs of recession. The same is true for the eyes, and it is even more apparent. In general, people over the age of 40, changes in the eyes there will be some such phenomena: Presbyopia presbyopia This is the most common phenomenon. Under normal circumstances, the eyes can see the distant scenery, but look close, you need to change the ciliary muscle contraction to the degree of projection, which is the same as the need to focus photography. To middle-aged people, the gradual hardening of the crystal, elasticity diminished, ciliary muscle strength decreased, the ability to adjust also worse. At this point, to see near the scene, especially in low-light reading newspapers, I feel vague, and this is presbyopia. Crystal opacity Another common phenomenon is the onset of opacity in the crystal. The formation of cataracts though in many ways