In a healthy eye, muscles have to squeeze the lens in order to focus up close images onto the retina.

在健康的眼睛中，肌肉必须挤压晶状体才能将近距离的图像聚焦到视网膜上。

As an object moves closer, light rays are hitting our lens at wider angles, so muscles squeeze the lens into a rounder shape to bring the focal point right onto the retina.

若物体接近，光线会以较大角度照到晶状体，因此肌肉挤压它变得更圆使得光线能刚好在视网膜聚焦。