Eyelashes have a protective effect. The upper and lower rims are lined up like guards, arranged on the edge of the split. Eyelashes are the second line of defense for the eyes. If foreign matter such as dust hits the eyelashes, the eyelids will be reflexively closed to protect the eye from external invasion. It has blackout to prevent dust, foreign matter, sweat from entering the eye and protecting the cornea and eyeball. Eyelashes also protect against UV rays. Eyelashes have the shortest life span in hair, and the average life span is 3-5 months. It is constantly updated. A developing eyelash can grow 1-2mm in a week after self-extraction. After about 10 weeks, the original length can be reached. Children's eyelashes are the longest and most curved. In daily life, some parents often remove eyelashes for infants and young children, in order to grow black and bright eyelashes. This method is not scientifically based, and sometimes even causes infections and other accidents, and destroys hair follicles, resulting in the loss of eyelashes.