Although, most refractive surgeries are currently effective and safe, these operations are capable of causing permanent changes. Therefore, the following points should be clarified before undergoing surgery. 1. I no longer wish to wear frames and contact lenses (contact lenses). I do not want to rely on glasses to correct my vision due to all the inconveniences in my work and life. 2. The doctor and patient communicate fully to choose an appropriate surgical plan. I have already had detailed communication with doctors and medical units qualified in refractive surgery, agreed and accepted the refractive surgery plan designed for my situation, and clarified the expected state and various possible problems after the surgery. The mainstream population undergoing refractive surgery is myopic patients of all ages. For excimer surgery, the age should be 18 years or older; myopia should be stable; myopia of 200 to 1,000 degrees and astigmatism of 400 degrees or less are more appropriate candidates. Patients with more than 1,000 degrees should be cautious. The average thickness of the cornea is 0.55 mm, and there is a lack of safe and reliable long term literature reports if the cut is too large. In a significant number of cases, excessive cutting can compromise visual quality. Postoperative glare, decreased contrast sensitivity and various higher order aberrations occur. Lens implantation in eyes with a lens may be considered for myopia greater than 1,200 degrees. If the age is over 50 years, clear lens removal may be performed. Patients undergoing laser surgery must undergo a thorough and detailed preoperative examination to rule out all possible contraindications (e.g., cone corneas, dry eye disease, and glaucoma). Some conditions with active lesions, such as conjunctivitis, blepharitis, keratitis, and chronic lacrimal sacculitis should be treated first.