1.What is excimer laser? Is there any damage to human body? Excimer laser is an ultraviolet beam invisible to the human eye. The excimer laser with a wavelength of 193 nm can precisely ablate the part of the cornea that is expected to be removed without damaging the surrounding tissues and other tissues and organs, and because it is a cold laser, it does not have a thermal effect on the tissues next to the irradiated area. With this precise ablation, the laser cutting does not penetrate the cornea, making it safer. Therefore, there is no side effect on the tissues inside the eye, and it will not cause side damage or sequelae. 2.When did excimer laser treatment for myopia start? Overseas since 1988 and domestically since 1993. 3.What is the principle of excimer laser treatment for myopia? Myopia is caused by the anterior and posterior diameters of the eye being too long or the front surface of the eye being too convex, so that external light cannot accurately converge on the fundus of the eye. Excimer laser keratomileusis (PRK and LASIK technology) is a computer-controlled excimer laser beam that slightly flattens the front surface of the eye, so that external light can accurately converge on the fundus of the eye to correct myopia. 4.What is the effect of the treatment? So far, the results of the treatment in China and abroad have been satisfactory, and the majority of patients have been able to remove their heavy myopic glasses once and for all. The naked eye vision after treatment can generally reach the corrected vision with glasses before treatment. 5.Who is suitable for the treatment? Those who are between 18 and 50 years old, and whose myopia and hyperopia are between 200 and 800 degrees with a stable prescription of 150 to 2000 degrees or combined astigmatism of 100 to 400 degrees in the past two years are suitable for treatment. 6.Who should not undergo treatment? People with infectious inflammation in the eye, cone cornea, glaucoma, cataract, fundus disease, or systemic diseases such as diabetes and collagen diseases. 7.What is PRK and LASIK? Excimer laser refractive keratectomy (PRK) is the most basic method of laser refractive surgery, which is based on the principle of removing the corneal epidermis and then removing a layer of corneal tissue by laser vaporization, the thickness of which depends on the degree. The thickness of the excision depends on the degree of the cornea, and since the release of the laser is completely computer-controlled, the accuracy is very high. After healing, vision is restored and myopia will be completely eliminated. Laserinsituskeratomileusis (LASIK) is a more scientific and rational refractive error correction procedure based on the PRK technique, which uses a corneal lamellar knife to cut a tipped flap and pneumatize the corneal stroma under the flap. The flap is then repositioned, and the procedure has a quick recovery. It can be used to correct myopia from 100 degrees to 3000 degrees, and is arguably the most perfect method for correcting myopia, hyperopia and astigmatism. 8.What are the advantages of LASIK? (1) wide range of adaptation: can correct 100-3000 degrees of myopia, can also correct astigmatism and farsightedness; (2) light post-operative reaction: no post-operative pain, no hospitalization, no clouding of the cornea; (3) fast recovery of vision: most patients recovered vision on the second day after surgery, no eye discomfort; 9, the effect of treatment is stable? Many years of theory and practice have proved that this wonderful laser makes the front surface of the eye flattened part will not regenerate and become convex again, so the effect of the treatment is very stable. If the pre-treatment myopia has been stable in recent years and the anterior and posterior diameters of the eye do not grow any longer, myopia will not reappear after treatment. LASIK has even less regression and is more suitable for high myopia (500 degrees or more). 10.What are the risks of the treatment? This technology uses the most advanced equipment in the field internationally, and the whole process of laser treatment is computer-controlled with an automatic eye tracking system, making the treatment highly safe and precise, so no serious after-effects have been found so far. Since the wavelength of this excimer laser is very short, 193 nm, it is impossible to penetrate into the eye, so there is no risk. 11.What procedures are required to undergo the treatment? After a detailed eye examination (about 1 hour), an appointment is made for registration and the treatment is scheduled to take place (PRK about 8 minutes/both eyes, LASIK about 20 minutes/both eyes) without pain or bleeding during the treatment. 12.How do I take care of myself after the treatment? After PRK treatment, you can go home and rest without hospitalization. Participate in various sports activities. 13.Are there any complications after treatment? There are symptoms such as foreign body sensation, tearing and soreness on the day of treatment, which will improve the next day and disappear after 2-3 days. Some people with high myopia may have some halos at night for a period of time, which may fade gradually.