瞳孔是眼睛的重要部份,瞳孔运动受瞳孔括约肌及瞳孔扩大肌的控制。这两种肌肉又分别受交感神经及副交感神经的支配,维持一定的紧张度,保持适当的瞳孔孔径。当经瞳孔投射到视网膜上的光线增强时,引起视网膜感光细胞兴奋,并由大脑传至瞳孔括约肌使瞳孔收缩。光线减弱时,瞳孔立即增大。这就是瞳孔对光的反射。除光线外,能 Pupil is an important part of the eye, pupil movement by the pupil sphincter and pupil to expand the control of the muscle. These two muscles are respectively dominated by the sympathetic and parasympathetic nerves, maintain a certain degree of tension, to maintain the appropriate pupil aperture. When the light projected onto the retina through the pupil is increased, the photoreceptor cells in the retina are excited, and the pupil sphincter is transmitted from the brain to the pupil to contract. When the light is weakened, the pupil immediately increases. This is the reflection of the pupil on the light. In addition to light, can