The indications for ICL lens implantation, or posterior chamber IOL implantation in crystalline eyes, are that the patient is at least 18 years of age, has had stable myopia for more than one year, has an anterior chamber depth of more than 2.8 mm, and has less than 2,000 diopters of myopia. Posterior chamber IOL implantation in crystalline eyes is a common means of correcting ultra-high myopia. By implanting an IOL inside the eye, the patient’s refractive defects are repaired, thus improving vision. However, this surgery has certain requirements for patients, suitable for adult myopic patients, and the myopia should not exceed 2000 degrees, and the myopia has been stable for more than 1 year. In addition, because the depth of the anterior chamber will become shallow after implantation of IOLs, the depth of the anterior chamber of the patient should be greater than 2.8 millimeters before the operation to be safer, otherwise there is a possibility of inducing glaucoma.