Nowadays, contact lenses of various colors are popular, and they are popular among young girls because they can make their pupils and eyes look bigger and more lively when worn. The main component of contacts is HEMA (hydroxyethyl methacrylate), which is used as a base for most contact lenses, and aids in adding some other hydrophilic chemical materials, which are then dyed or painted for eye beauty and orthopedic purposes. However, if these cosmetic contact lenses are not properly fitted or worn according to a doctor’s instructions, they can easily cause damage to the eyes. Since the opening of the contact lens specialist, many young girls have been treated for various types of eye problems due to the casual purchase, wearing and use of “contacts,” most of which are characterized by eye congestion, photophobia, pain and blurred vision after wearing the lenses, mostly keratitis. Most of these girls’ contact lenses come from online purchases, with no production license. They did not go through a standardized and accurate professional fitting process to obtain the correct parameters for their contact lenses. The lack of guidance from a professional optometrist also leads to serious consequences when wearing them for too long. Contact lens specialist tips: 1, consumers must choose to buy “contacts” contact lenses have a certificate of conformity and license products. Wearing unqualified or non-conforming contacts without these signs can lead to serious wearer corneal abrasion and even the risk of perforation. 2, “contacts” contact lenses are usually poor oxygen permeability, wear time as little as possible more than eight hours, need to strictly follow the instructions of a doctor. 3, because the composition of contacts contains hydrophilic substances, so it is easier to adsorb protein. In addition to daily disposable contact lenses, other colored lenses must be thoroughly rubbed and cleaned after removal, and protein removed on a regular basis. 4, the degree of contact lenses and frame glasses is a proprietary formula must be converted, non-professional prescription, may lead to inaccurate contact lens degree, damage the health of consumers’ vision. Finally, according to clinical observations, most of the “contacts” that cause eye diseases are black. Therefore, it is important to wear contacts with caution and to get the correct prescription and proper instruction from a regular optometrist.