The basic consensus on the range of degrees that can be corrected by laser surgery is that myopia should not exceed 1200 degrees, hyperopia should not exceed 600 degrees, and astigmatism should not exceed 600 degrees. If the preoperative corneal thickness, corneal refractive power and pupil and other factors, some myopia can occasionally do 1400 degrees, some myopia can only do 1000 degrees or even less. So what is the solution for myopia over 1400 degrees, such as 1900 degrees myopia or 2200 degrees myopia, for which corneal surgery is not suitable? Laser corneal surgery is to cut the cornea to make it flat and thin, which is a “subtraction” from a certain point of view, but if a lens is implanted in the eye, a very fine and thin lens, it can be regarded as an “addition”. For super high myopia over 1200 diopters, or high myopia with relatively thin cornea, or moderate myopia with too thin cornea, in principle, as long as there is no limitation of the intraocular space, especially the anterior chamber depth, and corneal endothelial abnormality, it is suitable for “additive” lens implantation. Additive surgery, refractive lens implantation to correct high myopia has been widely used in the United States and Europe. Without removing or destroying the corneal tissue and without sutures after the surgery, the treatment effect is very significant and has good safety. Taking ICL as an example, ICL is a purified collagen polymer (Collamer), which has good biocompatibility and has no adverse reaction in the eye. From the early anterior chamber type lens to the current posterior chamber type lens, this crystal “addition” surgery also has a tendency to expand more and more in China. In just a few years, the number of refractive lens implantation surgeries has increased dramatically. What are the other clinical advantages of “additive” surgery? The entire procedure takes only 5 to 15 minutes and does not require hospitalization. The incision is small and the lens can be folded without changing the structure or shape of the eye tissue, so the recovery is quick and you can work the next day. Under the slit-lamp microscope, the ICL fixed in the ciliary sulcus is the closest to the natural crystalline lens of a human being and has a better appearance. Since it is an “addition”, it is possible to remove the crystal if there is a problem, which means that this surgery is highly reversible. For people with myopia of 1,400 to 2,200 diopters or more, it can be assumed that ICL and other crystalline lens surgeries, which have characteristics that are not comparable to those of conventional laser surgeries such as LASIK, will surely flourish.