Refractive surgery is not an option for anyone to correct myopia, hyperopia and astigmatism. There are certain indications for refractive surgery. Before considering refractive surgery, patients need to know roughly for themselves whether they are suitable for the procedure. Factors that generally need to be considered are: 1. Age: In general, all types of refractive surgery are primarily for adults, aged 18-55. However, specifically for different surgical procedures and different eye conditions, the age requirement is different. For IOL implantation in crystalline eyes, the best age is 21-45 years old, because many patients are highly myopic, and 18 years old is also worried that it is not very stable and can be observed for a few more years. 45 years old and above, considering their decreasing adjustment power and the possibility of cataracts, clear lens removal can also be considered. However, this is not absolute. In fact, there are many people who have had ICL implantation at the age of 18 and have had good results. I have also performed ICL implantation on highly myopic patients in their 50s, and it also depends on the patient’s own eye condition, as well as their expectations and understanding of the procedure. There was a 55-year-old patient with high myopia who came to me from Qingdao for the surgery. I was a little hesitant at first. After a thorough eye examination and thorough communication, I operated on him. The surgery was chosen to preserve 200 degrees of myopia. Now, he is recovering very well after the surgery and is very satisfied with himself. Patients younger than 18 years old also have some cases where refractive surgery is possible or even necessary. 2.Stable refractive error: Generally speaking, before undergoing refractive surgery, it is best to have a relatively stable refractive error within the past two years. We generally consider changes within 100 degrees to be stable. Of course, this requirement is not absolute. This is because, in many cases, it is really difficult to determine whether the refractive error is stable or not. Mild to moderate myopia is easier to judge. Patients with high myopia, usually with glasses may not be sufficiently corrected, so the results of the optometry will be higher than the previous glasses, and can not be judged as the degree of instability. 3, mental health: Why is the issue of mental health raised here in particular? Because many patients who request refractive surgery will have a little bit of perfection in their character. Among them, some of them, may have too high expectations, and such people, after the surgery, will often have a variety of dissatisfaction. First of all, we should realize that refractive surgery is nothing more than an optical correction in place of glasses, and it is impossible to achieve vision beyond normal. Moreover, there may be some changes in the quality of vision after surgery, such as halos and glare around lights seen when driving at night. These symptoms do not cause too many problems. However, for people with poor mental health, they may be worried because of some changes in visual quality or because of problems such as dry eye. For patients with poor mental health, it is not completely impossible to do the surgery, but a good communication is needed before the surgery to establish reasonable expectations for the surgery. 4. Eye examination meets the conditions for surgery: A comprehensive examination is performed at the hospital where it is required, and the results of all examinations are within the range required for surgery before surgery can be scheduled. These examination results include: corneal thickness, corneal topography, intraocular pressure, cornea, fundus, etc. Of course, the examinations also include wavefront aberration, contrast sensitivity, and ocular AB ultrasound in order to fully evaluate the condition of the eye and to determine whether it is suitable for surgery on the one hand, and to select the most suitable surgical procedure on the other. Any active inflammation of the eye (including keratitis, iridocyclitis, etc.), organic eye disease, refractive interstitial clouding, etc., should be strictly evaluated, treated accordingly, and surgery should be carefully selected within certain limits. 5, physical health: Some systemic diseases that may affect corneal healing should also be carefully weighed. Systemic connective tissue diseases and immune disorders generally cannot be considered for refractive surgery. Diseases such as diabetes, hypertension, and cardiovascular disease should be treated and within safe limits before surgery is carefully selected. If you have some diseases yourself, you need to inform your doctor in detail, so that he or she can make a comprehensive weighing and judge whether to operate or not. 6.Surgery for special cases: For some patients who have already had refractive surgery or other eye surgery before, it is possible to consider receiving augmentation surgery under suitable circumstances. In general, patients who have previously undergone LASIK, LASEK, etc., and need surgery again if their vision is poor, generally need to be at least 3-6 months after the first surgery before they can choose surgery. If you have had previous surgery such as radial keratotomy (RK) or corneal transplant, you need to be stable for 2 years before considering LASIK surgery.