The eye is the most important organ of the human senses, and more than 90% of the information and knowledge received by the brain is obtained through the eye. It consists of the eye and the appendages of the eye, and there are more types of eye diseases. They include myopia, refractive errors such as farsightedness, astigmatism, and refractive error; strabismus, amblyopia, and nystagmus; various types of glaucoma, cataracts, retinal and retinal vascular diseases; and eyelid diseases including skin diseases of the eyelids, lid gland diseases, abnormalities in the position of the eyelids, and eyelid tumors. Lacrimal disease includes acute or chronic lacrimal gland inflammation, ocular dryness, tear point ectasia, tear duct obstruction, tear duct infection, and tear sac tumors. Conjunctival diseases include conjunctival sac microbes, parasites, conjunctivitis, allergic reactions, pigmentary degeneration. Keratoconus includes various keratitis, cone cornea, dystrophy, corneal tumor. Scleral disease, inflammation of the sclera, scleral chylomicron. Uveopathy, uveitis, ciliary tract infection, uveal tumor, congenital abnormalities of the uvea. Vitreoretinal disease, vitreous degeneration, vitreous hemorrhage, vitreous inflammation. Optic nerve disease including optic neuritis, optic nerve toxicity, optic nerve demyelinating disease, optic nerve ischemia, optic nerve compression disease, optic nerve tumor. Orbital diseases, orbital cysts, orbital vascular malformations. Ocular trauma and occupational diseases, chemical injuries, thermal burns, radiation eye injuries. In summary, the types of eye diseases are very complex, mainly including optometric diseases, infections, developmental abnormalities, vascular diseases, tumors, allergic reactions, traumatic diseases, etc.