Long ago, the ancients knew the important role of the eye as a sensory organ in the acquisition of visual information. The Emperor’s Classic of Internal Medicine states that the eyes have the function of “seeing everything, distinguishing between black and white, and examining the length”. Modern science confirms that more than 85% of the information that humans obtain from the outside world comes from the eyes, so the eyes are recognized as the first channel for information acquisition. The eye is like a senior fully automatic camera, the pupil is like an aperture, which automatically adjusts the amount of light entering the eye with the intensity of light; the cornea, crystal and vitreous humor are like a set of senior lenses, their transparent combination ensures the unobstructed light entering the eye; the retina is like a high-resolution light-sensitive film, the rich light-sensitive visual cells feel the light stimulation will occur complex photochemical reactions and produce bioelectricity Then the visual signal is sent to the visual center of the brain, and a precise, clear and colorful three-dimensional image is formed. When there is a problem with any part of the eye, it can have a major impact on vision. An alert and sensitive person with gleaming eyes, and people with poor visual function tend to have slow turning eyes and sluggish reactions, which are closely related to the amount of information taken in. When vision is good and more information is taken in, more associations and thinking are generated, thus the brain cells are always able to maintain good excitability. On the contrary, people with dull gaze tend to be slow to respond and their quality of life is often poor. Therefore, when a person has a problem with his or her visual function, early treatment or not is not only a matter of restoring the visual function, but also closely related to the health of the whole body, even family harmony and the scope of his or her social circle. Cataracts are the most common blindness-causing eye disease in China, and 100% of the elderly over the age of 80 have cataracts. The medical profession advocates that cataracts need to be treated as early as possible, and it is generally accepted that treatment is needed when vision is less than 0.5 or when it has an impact on life and work. Currently, there is a consensus in the ophthalmology community that there are no effective medications for cataracts, and that surgery is still the most effective, safe, and rapid method for restoring vision, especially for intermediate and advanced cataracts. So is cataract surgery scary or not? To what extent can vision be restored after surgery? The following is a brief introduction: I. Impact of cataract surgery on postoperative visual quality: In order to reduce the damage to the eye and postoperative astigmatism, cataract surgery has been continuously improved. However, the early intracapsular cataract extraction and modern extracapsular cataract extraction both suffer from complications such as greater damage to the eye structure and more obvious postoperative astigmatism, so that patients cannot achieve better visual quality after surgery. The recent development of cataract ultrasound emulsification is now recognized as an advanced and mature surgical procedure in the world. In fact, cataract surgery is not as scary as traditional surgery. Modern cataract ultrasonic emulsification surgery has actually reached the level of minimally invasive surgery in the real sense. The surgeon can start the surgery with some anesthetic eye drops on the surface of the eye 5 minutes before the surgery. 2. During the surgery, only a small opening of 2~3mm is needed to open the cornea, and the ultrasonic emulsification head is inserted to suck out the cloudy crystal through the physical emulsification of ultrasonic waves, and then a folded artificial lens is implanted through this small opening. A generally smooth surgery can be completed in only 10 minutes. 3, No sutures are required during and after the surgery, and vision can generally be restored the day after surgery. The effect of IOL on postoperative visual quality: IOL is a refractive lens used to replace the cloudy lens after cataract surgery. The function of the IOL can directly affect the visual quality of the patient after surgery. The maturation of IOL implantation technology and the improvement of its design process have led to the development of IOLs that are closer to the ideal natural lens, and now personalized IOLs are available. For example, multifocal IOLs can provide full visual acuity for distance, intermediate and near vision. Blue light filtering IOLs can reduce postoperative photophobia and blurred vision in cataract patients and play an important role in preventing age-related macular degeneration. There are also spherical aberration correcting IOLs and astigmatism correcting IOLs. Stereoscopic vision is a kind of advanced vision with three-dimensional sense based on simultaneous vision and fusion function. Normal stereo vision is a prerequisite for precise positioning of the human eye. In cataract patients, stereo vision is significantly affected and often does not recover immediately, even in the early postoperative period. Stereo vision is closely related to the following factors: (1) visual acuity. This is the recovery of visual acuity in one eye after cataract surgery. If the recovery of monocular vision is greater than 0.6, then the stereo vision of both eyes will be significantly improved. (2) Binocular visual acuity difference. The smaller the binocular visual acuity difference, the better the stereoscopic function. (3) Refractive error. The smaller the number of refraction and astigmatism, the better the stereopsis. (4) Binocular refractive error. This is the difference in the refractive power of both eyes. The larger the value of refractive error, the more serious the impairment of stereo vision. Cataract extraction and implantation of an artificial lens can overcome the refractive error in the lens-less state after cataract extraction and help to restore stereo vision after surgery. (5) Bilateral image inequality. Binocular image inequality refers to the formation of two images of the same object on the retina of both eyes with different size and shape, which can affect the normal fusion of both eyes and destroy the stereo vision function. Therefore, the smaller the image inequality value, the better the stereo vision. Therefore, although cataract surgery itself is quick, it is not a simple procedure. The surgeon needs to adjust the postoperative visual acuity, binocular visual acuity difference, refraction, binocular refractive error and binocular image inequality by selecting the appropriate procedure and IOL to help restore and re-establish good binocular visual function and thus improve the visual quality of the patient.