First of all, be clear. The important thing is to say it three times: laser surgery is a kind of cosmetic surgery. Laser surgery is a kind of cosmetic surgery. Laser surgery is a kind of cosmetic surgery. It has no therapeutic effect on myopia. Its principle is to remove a part of corneal stroma and form concave mirror, so as to achieve the purpose of refractive correction. The same principle as frame glasses and contact lenses. It is equivalent to having a pair of myopia glasses with a fixed degree in your cornea. First of all, be clear. Laser surgery is a kind of cosmetic surgery. Laser surgery is a kind of cosmetic surgery. Laser surgery is a kind of cosmetic surgery. Say the important things three times. It has no therapeutic effect on myopia. Its principle is to remove a part of corneal stroma and form concave mirror, so as to achieve the purpose of refractive correction. The same principle as frame glasses and contact lenses. It is equivalent to having a pair of myopia glasses with a fixed degree in your cornea. After the operation, most patients will have problems of visual fatigue and decreased night vision ability. So this is the first thing you need to know before the operation. Classification of laser surgery:

A. excimer is divided into PRK/IK/EK/TK.

B. half femtosecond.

C. all the minutes.

Briefly introduce IK, TK, semi-femtosecond and full femtosecond.

Don't talk about this kind of surgery, because no one has done it yet, such as the original PRK, so it's boring to talk about it.

The most common one is LASIK, that is, IK, which has the highest frequency and cheap price. The most advanced technology is full femtosecond.

LASIK. Let's start with LASIK. In order to facilitate your understanding, I found a very simple and intuitive picture on the Internet. I hope you can study more.

LASIK is mainly divided into two steps.

The first step is to make corneal flap, and the second step is excimer laser cutting. Let's introduce it with a short picture.

Now the corneal flap is completely reset. At this time, the corneal surface was not disturbed too much, so the postoperative recovery was faster. The thickness of the center of cornea has changed, which can play the role of contact lens.

The operation is over.

This is the basic principle of LASIK surgery. Generally, the operation time is very fast, only taking a few minutes.

Then LASEK. LASEK surgery (EK for short) is an excimer laser surgery for high and relatively thin cornea. The difference between LASIK and LASEK is that the former is performed on the stroma layer of cornea, while the latter is performed on the anterior elastic layer of cornea. The difference between LASIK and LASEK is that the former is performed on the stroma layer of cornea, while the latter is performed on the anterior elastic layer of cornea.