The so-called excimer laser is a mixture of two gases, fluorine and argon, after excitation and produced by a kind of ultraviolet light invisible to the human eye, its wavelength is only 193 nanometers, and no penetrating power, but it can break the chemical bond of the object, after breaking the tissue is vaporized, using such a principle, we are the degree of glasses to the eye, is equivalent to make a small lens in your eyes, to achieve the purpose of correcting vision. Excimer laser myopia surgery has become a very safe procedure since the first surgery was performed in 1988, after more than 20 years of continuous advances in ophthalmic medical technology and constant updating of equipment. The U.S. Food and Drug Administration (FDA) approved the excimer laser for the correction of myopia, hyperopia and astigmatism as early as 1995, stating that it is a safe and effective method for the treatment of refractive errors. According to statistics, nearly 40 million myopia patients worldwide choose laser treatment for myopia, and nearly 1 million myopia patients in China use laser treatment for myopia every year, including many world celebrities, sports and cultural stars who are well known to the public. Why do so many celebrities choose to have laser myopia surgery? One is because of the needs of work and life, and the other is the proven safety of excimer laser surgery. In addition to the excimer laser, the femtosecond laser creates a corneal flap by emitting an infrared laser that operates in pulses at a frequency of up to 1000k Hz or more. At the very front of our eye is a transparent membrane, anatomically called the cornea. Excessive curvature of the cornea, or a patient’s long eye axis, can cause myopia. Laser surgery is performed by changing the curvature of the corneal surface to change the refractive power of the cornea, allowing light to converge on the retinal macula and correcting myopia, which is the basic principle of corneal refractive surgery. The femtosecond laser is “blade-free” and has a very short duration of a few femtoseconds. The corneal flap made with the femtosecond laser is of uniform thickness, the position of the tip can be chosen at will, the cornea is biomechanically stable, the negative pressure ring is low, and there is no damage to the tissue. Because it does not use a knife, it is more suitable for people who are not suitable for traditional excimer laser in situ keratomileusis surgery because of thin corneas and high myopia. So what kind of people are suitable for myopia laser surgery? Patients between the ages of 18 and 55 years old. Patients with myopia of 100 to 1200 degrees, or combined astigmatism of 25 to 600 degrees, and farsightedness of less than 600 degrees, and who have been stable for two years are suitable for treatment. Such as systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis.