你知道嗎，我們人類平均每分鐘要眨眼十幾次，每2到6秒鐘就要眨一下。這是一種不自覺地運動。那麼，人類為什麼要這樣眨眼呢?下面這篇文章就來為您講述一下。
Blinking, as opposed to batting, our eyes automatically supplies two forms of moisture to our eyes, to keep them from drying out, and to keep foreign matter from entering and irritating our eyes. Eyelids themselves, our built-in "wind-shield wipers," are merely folds of skin, controlled by muscles capable of expanding and contracting so rapidly, that blinking does not impair our vision. Mother Nature lined the rims of our eyelids with 20-30 sebaceous, oil-producing glands, which are located between our eyelashes, and are invisible to the naked eye. Blinking automatically coats the eyelid and eyelashes with the lubricant it secretes, to prevent them from drying out.
Blinking also protects the eye from dryness by irrigating, not by irritating, the eye, The eyelid, through suction, automatically draws the fluid we cry with from the well we refer to as the tear duct over the eyeball, to irrigate, and to moisturize the eye. The process is similar to the manner in which the farmer uses water to irrigate his crops during a dry spell.
Yet another benefit of blinking, is to shield the eye from foreign bodies. Our eyelashes, short, curved, hairs, attached to the eyelids, serve as dust-catchers, as the blinking reflex causes them automatically to lower, when exposed to harsh elements. Nature endowed the camel with extraordinarily long, curly, eyelashes, to protect his eyes from sudden sandstorms in the desert. Incidentally, the "camel eyelash" look is one many women attempt to duplicate by using an eyelash curler! Eyebrows, by the way, also serve their purpose, as they catch the run-off perspiration produces.
