1.Laser thermal effect-retinal laser photocoagulation: The laser thermal effect causes the target tissue to coagulate, thus scarring the target tissue to achieve the treatment purpose. Indications: diabetic retinopathy, retinal vein obstruction, retinal perivasculitis (Eales disease), retinal fissure, Coats disease, retinal tumor, central plasma retinal chorioretinopathy, etc. 2, the ionization effect of laser-Nd: YAG: through the laser focus out of a small area of space of material ionization, and then pulse blasting to achieve the purpose of treatment. Indications: Lens capsule membrane truncation: posterior cataract, iris peripheral resection, etc. 3.Photochemical effect of laser-photodynamic therapy (PDT): Through intravenous injection of photosensitizer accumulates in high concentration in abnormal blood vessels, and activates the photosensitizer under the irradiation of cold light source to cause chemical reaction, thus causing coagulation, necrosis and atrophy of abnormal blood vessels to achieve the treatment purpose. Indications: Subretinal choroidal neovascularization: age-related macular degeneration (age-related macular degeneration), central exudative retinal chorioretinopathy, highly myopic macular degeneration, etc. It is characterized by almost no damage to normal tissues, significantly improving and preserving vision; and is the only laser therapy for lesions that effectively acts on the central macular recess.