Since 1949, when the first IOL was implanted in the eye by Dr. Ridley in England, the IOL has evolved tremendously in terms of manufacturing process, materials and implantation technology, which has attracted the attention of the entire medical community and is of epochal importance. The IOL is currently the safest and most effective way to correct refractive errors in aphakic eyes. It overcomes the problems that exist with frames and corneal contact lenses. Advantages of the IOL 1. Small magnification of the object. The anterior chamber IOL magnification is 4%, the iris plane magnification is 3%, and the posterior chamber IOL magnification is less than 1%. It can be used for monocular lens-less eyes. 2.Smaller spherical aberration. 3.Rapid recovery of visual acuity after surgery, can establish binocular monocularity and stereo vision. The postoperative corrected visual acuity greater than 0,5 reaches 92-97%. 4.IOL implantation for children has an important role in the prevention of amblyopia. 5.No annular dark spot and normal peripheral vision. 6.Wide range of indications, most cataract patients can receive IOL implantation. Disadvantages of IOL 1. Measurement error of IOL degree and postoperative refractive error. 2. There are obvious adjustment problems after IOL implantation, and the effect of near vision is poor. 3, post-operative photophobia, glare, macular light damage, medical astigmatism. 4.Improper surgery is prone to complications, such as dislocation and deviation of the artificial lens. IOLs are suitable for most cataract surgery patients. 2. Patients older than 3 years old (including 3 years old) with aphakic eyes in one or both eyes. IOLs are not suitable for 1. Patients younger than 2 years old with rapid changes in eye axis and corneal curvature, and difficult to measure the appropriate IOL degree for implantation. 2, congenitally small eyes, small corneas patients should be cautious. 3, the number of corneal endothelial cells is abnormal. 4, there are systemic or ocular diseases that are not suitable for IOL implantation. IOL clinical evaluation and development trend 1. IOL is the most effective and best method to correct aphakic eyes. 2. The poor adjustment ability, refractive error and complications of IOLs should be taken seriously. New artificial lenses that are more in line with the physiological function of the human eye will continue to emerge. Such as the proposed adjustment IOL, multifocal IOL, injection IOL, aspheric IOL, tinted IOL, astigmatic IOL, etc.