Is “laser blindness” true or false? –False: Lasers play a vital role in the treatment of many fundus diseases. By applying the photochemical reaction of the laser, we can treat macular degeneration, benign tumors of the fundus, such as choroidal hemangiomas. This laser reacts with the photosensitizer injected into the body, minimizing or even negligible damage to normal tissues, and the laser energy is focused on the diseased tissue to destroy it. There is no pain or other discomfort to the patient during the treatment. Applying the thermal effect of the laser, we have treated many ischemic diseases of the fundus, such as diabetic retinopathy and retinal vein obstruction. When the small blood vessels in the fundus are blocked, the current medical technology is not yet able to open the blocked blood vessels, the retinal cells in the area governed by these vessels lose their light-sensitive ability to die due to ischemia, we can only sacrifice this part of the retina that has died and hit the laser, so that the local scar is formed and no longer needs blood, the organism will not grow new blood vessels in this area, once the new blood vessel generation will lead to massive bleeding, causing Once neovascularization occurs, it will lead to massive bleeding, causing blindness, or even neovascular glaucoma, which is painful and blind. Therefore, laser is an effective way to stop the progression of the disease and prevent blindness. Why do some patients go blind after one laser treatment? –Laser treatment is only a remedy and does not stop new blood vessel blockages. In diabetic retinopathy, for example, it takes some time for the laser spots to form and work, and only a sufficient amount of laser spots can achieve the therapeutic effect. When the fundus lesion is serious, there is a large amount of bleeding and fiber proliferation, the laser treatment cannot be completed as planned; if the blood sugar, blood pressure and blood lipid are not fully and effectively controlled, and the blockage of blood vessels in the fundus develops further, the therapeutic effect of laser cannot catch up with the deterioration of the disease When there is carotid artery obstruction and the blood supply to the eye is severely inadequate, fundus laser treatment is not enough to improve the ischemic condition of the fundus, and in all these cases, we cannot prevent the occurrence of blindness by applying laser treatment only. Therefore, laser treatment is only a treatment tool, and the treatment of the cause of the disease should not be neglected. Active control of blood glucose, blood pressure, and lipids, and improvement of systemic conditions remain crucial. Lasers have been widely used since the 20th century, and with the development of science and technology, we continue to develop and utilize the properties of lasers to make them better serve us. Laser blindness is not the fault of lasers, but how we use them. Scientific and rational use of lasers will provide the possibility to improve vision and maintain it.