Implantation of trifocal IOLs is a technical means to solve the problem of patients being able to obtain clear vision when looking at distance and near after cataract surgery. However, there are also certain side effects: 1. Some patients may experience glare, because trifocal IOLs produce different color effects through different areas of the crystal optical area, and focus the original external light into a focal point, which is divided into three parts: distance, middle distance and near distance, which has a certain impact on the imaging effect and makes patients easily experience glare such as haloes when looking at light sources. 2, Patients will experience reduced contrast sensitivity, also due to inherent defects in the optical design of trifocal IOLs.3. Patients with posterior cataracts, after laser posterior capsulotomy, usually the effect of trifocal IOLs cannot be fully exerted, because part of the refractive area will be blocked by the posterior cataract.