It has been reported that the number of patients who have been fitted with keratoplasty lenses in China has reached 1.4 million. The safety of keratoplasty lenses is gaining more and more attention, and it is worth thinking about how to improve safety and what principles to grasp. Corneal shaping lenses (i.e., OK lenses) have been studied by ophthalmologists in major hospitals and confirmed to be effective in controlling and delaying the development of myopia. Professor Xie Peiying’s research results in an average annual increase of 18 degrees in adolescent students, foreign research results in an increase of even less than 10 degrees, and some research results in an annual increase of more than 20 degrees. This growth rate is much lower than the growth rate of wearing frame glasses, I encountered in the clinic with frame glasses even increased by 200 degrees per year, increased by 100 degrees is common, of course, there is no increase, very little. So the role of keratomileusis is indisputable. First, the design of the keratoplasty lens: four zones and seven arcs or even multi-arc design The four zones are mainly the base arc zone (BC), also known as the central optical zone or treatment zone; reverse arc zone (RC); positioning arc zone (AC), also known as the fitting arc zone; and peripheral arc zone (PC), also known as the circumferential arc zone or side arc zone (memory bra + p zone). Second, the mechanism of myopia control and myopia control principle of keratoconus 1, blink when the massage effect. 2.The hydraulic effect of tear fluid. 3, the change of corneal morphological factors. 4, the mechanical compression effect of hard lenses. 5.Microscopically: the corneal epithelial cells undergo redistribution and the corneal tissue morphology is changed without physiological lesions. 6, corneal epithelial cells (thickness 50um) central thinning, mainly epithelial layer thinning, reversal arc area thickening 7, central corneal flattening, mid-periphery convexity, change the central corneal refractive power, reduce myopia, restore naked eye vision. 8.Change the peripheral refractive power of the cornea, thus the retinal peripheral defocusing phenomenon, so that the hyperopic defocusing becomes myopic defocusing, thus controlling the growth of the posterior bulging of the eye image. 9, can absolutely control the growth of the eye axis, thus slowing down the control of myopia increase. 10.After 1 month of stop wearing, the cornea will return to its initial shape. Third, the applicable population 1, no eye disease. 2.Above 8 years old. 3.Good health environment, good hygiene habits, and compliance with medical advice. 4.Myopia below 600 degrees, astigmatism below 175 degrees. 5.Corneal flat opening value is greater than 39D and less than 46D. 6.Adolescents with rapid myopia progression or with significant myopia progression. 7.Safe and effective after trial wear. Fourth, a little thinking about safety keratoplasty lens is, after all, a contact lens worn at night, so safety is the first, is also our eternal pursuit of the goal. So how to do safe to wear it? I think the following points are worth noting: (a) good communication, patient’s choice The child and parents are psychologically healthy, have some financial ability, have some acceptance of new things, and can fully understand the keratoplasty lens through communication. It is not completely stop myopia deepening, of course, there are many patients who wear myopia for a long time without deepening, it needs to be worn overnight for a long time, high number of plastic effect is not good also can choose to wear during the day. Do not wear the degree will rebound, stop wearing 1 month after the cornea can be restored to the form before the fitting. (B) the choice of lens manufacturers good lens material, good lens design, good lens supplier is also very important. High oxygen permeability, more reasonable lens design, increased tear exchange, application of plasma technology to make the wetting angle smaller, increased wearing comfort, decreased adhesion to bacteria, and increased wearing safety. The replacement rate of certain lenses by the manufacturer can relieve the worries. (C) detailed examination before wearing, strict screening of indications exclusion of eye diseases, medical optometry, fundus examination, eye position examination, corneal diameter, pupil size (light/dark), corneal topography, corneal curvature, axial length examination, eyelid tightness, lid width strict control of indications and contraindications, exclusion of cone corneas, the examination process to observe the parents and patients’ compliance, this is important. (iv) Trial wear assessment – the key to the key 1. Safety is based on having mobility. 2. The principle of preferring loose to tight. 3.The principle of centering the lens. 4, four zones of fluorescent staining: base (staining 4 to 5, 5mm) anti (0, 6 to 0, 8mm) fixed (1, 6 to 2mm) week (0, 5mm). 5, fitting experience summary, each interval, interval and interval fluorescence dye ** condition how, are the need for continuous awareness summary to improve, this is the key to fitting. (E) the regular follow-up after the fitting the next morning wearing glasses to review 1, not found any complications: maintain the original way of wearing glasses until the next review. 2.Deviation and hyperactivity: increase the diameter of the lens. 3.No flattening of corneal curvature (bridging may exist), too steep base arc, too deep retraction, too large positioning angle need to change lenses for trial wear adjustment Regular follow-up observation of eye health, naked eye visual acuity, refractive index examination, corneal topography, timely detection of problems and problem solving. Regular follow-up, discomfort at any time to the hospital follow-up is very important, because the early conjunctival corneal infection timely use of antibiotics can be effectively controlled, once delayed, the development of the disease from light to heavy, is very troublesome. Therefore, this statement must be repeated with patients and parents to attract attention. The improvement of a skill is based on continuous practice, summary, plus continuous learning, in order to gradually become comfortable with it, so learning to learn again, practice practice again is the best advice. Welcome your criticism and correction.