视力是人体分辨物体形状的感觉能力。物体的光线,经过屈光系统的屈折后,在视网膜上结成形象,并产生一系列光化学反应,转化成神经冲动,由视神经传至大脑枕叶视觉中枢,就产生了看到物体的感觉。在视网膜黄斑部的中央凹处,由于圆锥细胞排列最密集,并且每个细胞均有一条传导纤维与达到大脑枕叶皮质的神经纤维相连,是形觉最敏锐和完善的部位。这个区域内的视力称为中央视力,所以视力强,看到的物体最清楚。平常所说的视力,就是指中央视力而言。在视网膜黄斑部中央凹之外的其余网膜周边部分,圆锥细胞愈向周边愈稀少,杆状细胞则逐渐增多,而杆状细胞是数个细胞共有一条传导纤维的,视力较中央视力为弱,称为周边视力。当眼注视某一点且不活动时,周边视力所能看到的范围称为视野。视力的检查是一般健康体格检查中重要项目之 Vision is the ability of the human body to perceive the shape of an object. Objects of light, after refraction refractive system, in the retina to form an image, and produce a series of photochemical reactions, into nerve impulses, transmitted from the optic nerve to the occipital lobe of the visual center, it produced the feeling of seeing objects. In the fovea of ​​the macula, the most sensitive and perfect shape is found in the conic cells, which are most densely arranged and each have a single conductive fiber connected to the nerve fibers that reach the occipital cortex of the brain. Eyesight in this region is called central vision, so eyesight is strong and objects seen are most clearly visible. Normally referred to as the vision, refers to the central vision in terms of. In the peripheral retinal macula than the remaining part of the omentum, the more conic cells around the more scarce, rod-shaped cells are gradually increased, while the number of rod-shaped cells is a total of a few conductive fibers, visual acuity than the weak , Known as peripheral vision. When the eye looks at a certain point and is inactive, the range of vision that can be seen by peripheral vision is called vision. Eye examination is a general health examination important items