The picture shows the pattern of human eyeball structure. Please answer the following questions according to the analysis of the picture: (1) The light reflected by external objects passes through the structure of various parts of the eyeball. The eyeball consists of an eyeball wall and contents. The eyeball wall includes an outer membrane, a middle membrane and an inner membrane. The front of the outer membrane consists of a colorless and transparent cornea and a white and tough sclera. The media is composed of ④ iris, ⑤ ciliary muscle and ② choroid, with iris in front, which is opaque and has melanin, commonly known as black eyeball, and white people are blue, commonly known as blue eyes; Intima is ⑥ retina containing photoreceptor cells, which can form an object image; The contents are composed of aqueous humor, ⑧ lens, and ⑨ glass body. The lens is like a biconvex lens, which refracts light, so that the light reflected by different objects near and far can fall on the retina. There is a pupil in the center of the iris, the size of which can be adjusted to control the light entering the eyeball. The glass body is a transparent colloid, the largest.

(1) The process of vision formation is as follows: the light reflected by external objects passes through ① cornea and aqueous humor, enters the eyeball from the pupil, and then forms a clear object image on ⑧ retina through the refraction of ⑧ lens and ⑨ vitreous body. The object image stimulates the photoreceptor cells on retina, and the nerve impulses generated by these photoreceptor cells travel along the optic nerve to the visual center of cerebral cortex, thus forming vision.

(2) When looking at the near objects, we must increase the convexity of the lens through the contraction of the ciliary muscle, so that the near objects can fall on the retina, so that we can see clearly.

If you work at close range for a long time, such as reading, writing, watching TV, playing game machines, etc., your eyes will be nervous for a long time, your head will lean forward, your eyeball will be constantly congested, your intraocular pressure will increase correspondingly, and your extraocular muscles will be nervous and oppress your eyeball, or your blood circulation will be hindered due to the traction of vortex veins during adjustment, which will weaken the resistance of the sclera and lead to excessive convex lens, which cannot be restored to its original state. In severe cases, the anterior and posterior diameter of the eyeball is too long, and the object image formed by the light reflected from distant objects falls in front of the retina, so the distant objects cannot be seen clearly, resulting in myopia, which needs to be corrected by wearing a concave lens.

So the answer is:

(1) Retinal visual center (or a certain area of the brain)

(2) [8] lens fovea