Following the development of the techniques of phacoemulsification and intraocular lens (IOL) implantation as well as the advances of materials of IOL, the better design of aspheric, multifocal and loop surface IOL, the cataract surgery has become a refractive surgery that can enhance the optical performance of the eyes. Therefore, cataract surgery has entered the era of pursuing quality of vision and visual comfortable level to meet the requirements of the patients. Patients after the cataract surgery not only can see but also can see clearly and comfortably. Therefore, more and more methods for the measurement of functional vision have been developed. These methods are important in the evaluation of quality of vision in patients with early stage cataract and after the cataract surgery.