What are the precautions for choosing colored contact lenses?

Colored contact lenses are highly praised by young people who pursue individuality and fashion because of their various beautiful colors and styles, and they can make eyes look bigger and brighter. But do you know what precautions should be taken when purchasing and using colored contact lenses and their care products?

Contact lenses are medical devices

Let's first take a look at how colored plano contact lenses are defined. Contact lenses are classified as Class III medical devices in China. They are lenses that are directly attached to the tear layer on the surface of the cornea. They correct refractive errors and treat certain eye diseases by changing the refractive power of the eye.

The country defines Class III medical devices as the highest level, which refers to medical devices that are implanted in the human body to support and maintain life, are potentially dangerous to the human body, and must be strictly controlled for their safety and effectiveness. It can be seen that colored contact lenses are not "cosmetics" as defined by everyone, but a medical device that must be strictly regulated like artificial heart valves and artificial kidneys.

Colored plano contact lenses are contact lenses that are tinted to beautify and decorate the eyes.

So how exactly do these colors adhere to contact lens lenses?

There are usually two ways: one is the "sandwich" method, which is to press a layer of iris-like color between two soft lenses. Although this lens reduces the impact of pigments on the eyes, it makes the lens thicker and less comfortable, and more importantly, affects the oxygen permeability of the lens, which can easily lead to corneal hypoxia and affect the normal physiological metabolism of the cornea; the other is to color the lens directly, which is more irritating to the eyes, and the attached pigment will also affect the oxygen permeability of the lens.

Choose the right purchase

According to the relevant regulations recently issued by the State Food and Drug Administration, we would like to remind you to pay special attention when purchasing colored plano contact lenses and their care products:

★You should purchase from a medical device operating company that has the relevant business license, and check whether the purchased product has obtained a medical device registration certificate. Carefully check the product packaging to see if there is information such as the medical device registration certificate number, manufacturer name, production date, etc., and keep the purchase receipt properly.

★Imported colored plano contact lenses and their care products should also be accompanied by Chinese labels and instructions.

★To query the relevant information of medical device registration certificate, please log in to the "Data Query" column of the website of the State Food and Drug Administration.

★Never buy unregistered products from informal merchants or online stores just to save money.

When choosing colored plano contact lenses, in addition to the above product information, you should also pay attention to whether the parameters of the lens match the curvature of the cornea. Because if the lens is worn too loose, the comfort of wearing the lens will be significantly reduced, and it may also cause corneal epithelial damage, lens displacement, etc. If the lens is worn too tightly, although the foreign body sensation when wearing the lens will be reduced, this is not a good phenomenon, because wearing it too tightly will make the lens tightly attached to the cornea, which is more likely to cause corneal hypoxia, thereby causing serious complications.

Things to know when wearing glasses

There are also strict time limits for wearing colored plano contact lenses. Generally, contact lenses should not be worn for more than 8 hours a day. For contact lenses with poor air permeability, the wearing time should be shortened. It is recommended to use them for a short time when necessary, and never wear them from morning to night. Wearing contact lenses for a long time can easily lead to corneal hypoxia, corneal damage, and even serious eye diseases such as keratitis and conjunctivitis.

So, how do you wear colored contact lenses safely?

First of all, colored plano contact lenses are not suitable for everyone. Before buying colored plano contact lenses, you must go to a regular institution for a comprehensive eye examination, including the anterior segment, fundus, intraocular pressure, refractive power, corneal curvature, corneal endothelium, tear secretion, etc., and use these examination results to determine whether you are suitable for wearing colored plano contact lenses.

In addition, professionals should also understand the family history and past history of the wearer, whether there are genetic, immune and other diseases, because these systemic diseases will also affect the safety of wearing glasses.

Secondly, on the premise that it is suitable to use contact lenses, everyone should also choose lenses that match the curvature of the cornea. A good fit is the basis for ensuring safe wearing of lenses, and correct lens care methods are the guarantee of safe use.

In addition to the strict control of wearing time mentioned above, the following care requirements should also be kept in mind:

●Be sure to clean your hands thoroughly before touching contact lenses and do not have long nails to avoid contaminating or damaging the lenses.

●Clean the lenses carefully before and after wearing them.

●After removing the lens from the eye, be sure to soak it in a special care solution for disinfection.

●Except for special care solution, contact lenses cannot be soaked in other liquids.

●If you need to put on makeup, put on your contact lenses first and then put on makeup, and take off your contact lenses first and then remove your makeup.

●It is not recommended to wear contact lenses when taking a bath, swimming, or when there is strong wind and dust or the air is polluted.

In addition, any contact lens has a service life. You should replace the lenses regularly according to their service life. Even if the lenses have not expired, they should be replaced in time if they are damaged. Wearing lenses beyond the expiration date can easily lead to keratitis and conjunctivitis.

Only by carefully following the correct care methods for contact lenses to use, remove, clean, disinfect and store them can we ensure the safety of wearing lenses.

Author: Wang Yanxia, ​​senior optometrist at Beijing Tongren Hospital

Review | Expert of National Health Science Expert Database

Zhao Mingwei, chief physician and professor of ophthalmology at Peking University People's Hospital

Planning | Tan Jia

Editor | Liu Yang