Contact lenses have been around for more than a century. For reasons of aesthetics, convenience, and work requirements, countless people around the world are enjoying the benefits of wearing contact lenses. In today’s increasingly technologically advanced world, contact lens technology has also been updated by leaps and bounds, and a new type of contact lenses called breathing contact lenses – RGPs – have become fashionable in Europe and the United States. Are you a contact lens wearer who has noticed the development of contact lenses? Have you updated your contact lenses? Do you know that your contact lenses can “breathe”? In our daily life, contact lenses usually refer to soft contact lenses, also called soft lenses, while contact lenses can actually be categorized into soft contact lenses and rigid corneal contact lenses, with soft lenses accounting for the majority of wearers at present. The material basis of soft lenses is HEMA (hydroxyethyl methacrylate), the best soft lenses oxygen permeability coefficient (DK value) is only 20, and there are charged chemical groups in the composition of the material, which will adsorb substances with opposite charge in the tear fluid and form a layer of precipitate film on the surface of the soft lenses, which affects the permeability of the lenses and the oxygen conduction, and the protein deposits can’t be removed completely even if used in full accordance with the care standards. Even when used in full compliance with the standard of care, the protein deposits cannot be completely removed. Did you know that our cornea also needs to “breathe” oxygen, 7% oxygen is the minimum physiological requirement for the eyes, once the cornea is deprived of oxygen, there will be dryness, fatigue, foreign body sensation, blurred vision, and in serious cases, corneal neovascularization, keratitis, macropapillary conjunctivitis and other problems will occur, which will cause harm to the wearer. RGP is the abbreviation of Rigid Gas Permeable Contact Lens, which means Rigid Oxygen Permeable Corneal Contact Lens in Chinese. From the name, we can know that this contact lens is hard, and it has the reputation of “contact lens that breathes”. Compared with soft lenses, the material of RGP is PMMA (polymethylmethacrylate) with the addition of silicone, fluorine and other polymers, coupled with the fact that the lens is very small and is only worn on the tinted part of the eye, and it can move 1-2mm when blinking, which ensures a good exchange of tears so that the metabolites of the eye on the back side of the lens can be cleared out, and the oxygen in the air can enter. Compared with soft lenses, RGP has the following unique advantages: ① high oxygen permeability ensures that the surface of the eye receives sufficient oxygen, greatly reducing complications compared to ordinary soft lenses, and it is the safest contact lens to wear at present, and its continuous wearing time can reach up to 30 days, which is incomparable to soft lenses; ② it is well shaped with good optical performance to ensure that you get clear vision, even if it is a high degree of astigmatism, irregular astigmatism, aphakic eyes, or aphakic eyes, Even for high astigmatism, irregular astigmatism and aphakic eyes, you will get good correction; ③ It has hard material, easy to use, easy to take care of, and has a much longer life span than ordinary soft lenses; ④ In addition, a large number of clinical studies have shown that it can also slow down the development of myopia in adolescents, making it one of the ideal choices of vision correction for adolescents. At present, it has been widely applied and carried out in foreign countries, and the fitting rate of RGP among patients wearing contact lenses is 55% in Japan, 40% in Europe and America, and 30% in Hong Kong and Taiwan, and the number of myopic patients wearing RGP in the domestic optometry clinics has been increasing year by year, and the RGP has been designated by the Ministry of Health of the People’s Republic of China as a “ten-year and one hundred items” promotion project (the only project of the ophthalmology department). RGP has been designated by the Ministry of Health of China as the “100 items in ten years” promotion program (the only program in ophthalmology). You may ask: Can I wear RGP? I tell you, the indications of RGP are quite wide: 1. Myopic patients with deepening myopia, especially teenagers with myopia can slow down the development of myopia through it; 2. General myopia, hyperopia, astigmatism, refractive error; high myopia, high hyperopia, high astigmatism, irregular astigmatism; 3. Patients needing to wear lenses for a long period of time (overnight); 4. All patients who do not have the ability to adapt to wear soft lens again and are unable to adapt to wear soft lens again. All patients who are unable to give up contact lens wearers due to various complications caused by soft lens wear; 5. Patients with conical cornea; 6. Patients with presbyopia can wear bifocal RGP; 7. Patients with irregular corneal astigmatism due to various kinds of refractive corneal surgeries (e.g., RK, PRK, LASIK), corneal transplantation, and keratoconus (e.g., corneal trauma, keratitis); 8. People with traumatic injury to the eye, no lens after surgery, and no iris; 9. Patients who are in need of long wear (night wear); 11. Patients who need to have long wear, or need to have long wear. Although RGP has many advantages, patients with the following conditions need to be careful and to be decided by the doctor whether it is suitable for wearing: 1. diabetic patients, thyroid protrusion and psychiatric patients; 2. expectant women, one-eyed people; 3. corneal rim or near the bulging area of the person (eg, pterygium or blepharosphenoid spot); 4. severe dry eye; 5. children must be accompanied by a guardian for the test; 6. eye has a history of surgery. Patients need to be examined by a doctor before deciding whether they can be fitted. Now you can consider whether you or your friends or relatives need a customized contact lens that “breathes”. If you are in need of contact lenses, please consult a doctor who is familiar with ophthalmology and optometry, and then choose a regular eye hospital, through a comprehensive examination, including comprehensive optometry, slit lamp corneal microscopy, funduscopy, corneal curvature, tear fluid and other examinations, according to the examination data, through the trial fitting assessment, to give the most accurate and scientific fitting, customized contact lenses suitable for the health of your eyes. In the future, the practice of purchasing a pair of soft contact lenses based on spectacle prescription alone will be phased out. RGPs are safe to wear under the guidance of a medical professional and with regular checkups. Adults and children of any age can wear RGP lenses with parental assistance as long as they are competent enough to know how to use and care for them. With the right lenses, vision can equal or exceed that of frames, and the wider field of view without the obstruction of frames allows RGP lenses to qualitatively improve vision. It is important to note that there is generally an adaptation process for RGP wear, usually around 2-4 weeks, at first there will be a foreign body sensation, vision fluctuation and dryness, after this period of time, the feeling will get better and better. The wearing time can be gradual from less to more until fully adapted, wearing discomfort, should be removed immediately and accept the ophthalmologist’s examination. There is also a special class of rigid corneal contact lenses as keratoplasty lenses, which are designed as gas permeable rigid contact lenses that are opposite to the corneal surface of the human eye with multiple arcs, which can reduce myopia, significantly improve naked-eye vision, and control the development of myopia by wearing them in the eyes at night during sleep, so that the cornea undergoes a reasonable plasticizing effect. Keratoplasty lenses have a wide range of indications, not only limited to adolescent myopia patients, but also myopia patients who often participate in recreational and sports activities and do not want to wear glasses during the daytime. In addition, Keratoplasty lenses are also particularly suitable for low and moderate myopia patients who are engaged in special occupations, who need to have good eyesight but are not permitted to wear glasses or are unwilling to undergo myopic surgery, such as police officers, military personnel, deep-sea divers, pilots, and so on. Corneal reshaping lenses are also effective for patients who have poor vision after myopia surgery and need to be recorrected. However, it should be reminded that the corrective effect of keratoplasty has a certain degree of reversibility, once stopped wearing the cornea shape will gradually return to its original shape, the speed of its return is related to the refractive status of the eye and the length of time of wearing the lens and other factors. After reading this, you should have a further and comprehensive understanding of contact lenses, and can proactively make more suitable, healthier and safer choices for your eyes. Your health is the wish of our healthcare professionals! We hope that everyone has a pair of bright windows of the soul!