The meridional fibers extend from the peripheral ends of the suspensory ligaments to the corneoscleral junction. When these muscle fibers contract, the peripheral insertions of the lens ligaments and are pulled medially toward the edges of the cornea, thereby releasing the ligaments’ tension on the lens. The circular fibers are arranged circularly all the way around the ligament attachments so that they contract, a sphincter-like action occurs, decreasing the diameter of the circle of ligament attachments; this allows the ligaments to pull less on the lens capsule.

The ciliary muscle is controlled almost entirely by parasympathetic nerve signals transmitted to the eye through the third cranial nerve from the third nerve nucleus in the brain stem. Stimulation of the parasympathetic nerves contracts both sets of ciliary muscle fibers, which relax the lens ligaments, thus allowing the lens to become thicker and increase its refractive power. With this increased refractive power, the eye focuses on objects nearer than when the eye has less refractive power. Consequently, as a distant object moves toward the eye, the number of parasympathetic impulses impinging on the ciliary muscle must be progressively increased for the eye to keep the object constantly in focus.

As a person grows older, the lens grows larger and thicker and becomes far less elastic, mainly because of progressive denaturation of the lens proteins caused by light and the inability to regain their native state. Therefore the ability of the lens to change shape decreases with age. The power of accommodation decreases from about 14 diopters in a child to less than 2 diopters by the time a person reaches 45 to 50 years of age; it then decreases to essentially 0 diopters at age 70 years old. Thereafter, the lens remains almost totally nonaccommodating, a condition known as “presbyopia”.

Once a person has reached the state of presbyopia, each eye remains focused permanently at an almost constant distance; this distance depends on the physical characteristics of each person’s eyes. The eyes can no longer accommodate for both near and far vision. To see clearly both far and near, an older person must wear bifocal glasses with the upper segment focused for far-seeing and the lower segment focused for near-seeing.

Another problem with the lens is the cataract. A cataract is a cloudy or opaque area or areas in the lens. In the early stage of cataract formation, the proteins in some of the lens fibers become denatured due to exposure to light. Unable to regain their native state, these same proteins later coagulate to form opaque areas in place of the normal transparent protein fibers. Finally the light transmission is obscured so greatly that it seriously impairs vision.  Though this condition can be corrected by surgical removal of the lens, when this is done, the eye loses a large portion of its refractive power, which must be replaced by a powerful convex lens in front of the eyes or an artificial plastic lens implanted in the eye in place of the removal lens.

The lens of ordinary people is composed of the protein and capsule. While absorbing 380nm-780mn visible light and ultraviolet light, the protein fibers will become denatured by light, but fail to recover the native conformation, and finally lead to such visual impairments as presbyopia and cataracts, etc. The protein in the lens of the New Human Line can be renatured; that is, when the lens become denatured due to exposure to light, the function of protein renaturation can have the denatured lens immediately regain its native state. Therefore, the New Human Line are allowed to be neither afraid of direct exposure to the sunlight nor afflicted with presbyopia and cataracts.