The cornea, commonly known as the “black eye”, is a slightly convex, sub-circular, transparent structure located in the center of the anterior part of the eye and is involved in forming the outer layer of the eye wall. The cornea protects the intraocular tissues and maintains the shape of the eye. The cornea is also an important refractive interstitial, which is the pathway through which external light enters the eye and is imaged on the retina. Therefore, the maintenance of normal corneal structure and function is a prerequisite for clear vision. A foreign body that is attached to the surface of the cornea or embedded in the cornea is called a corneal foreign body. Corneal foreign bodies can be single, multiple or even diffuse. First, the types and sources of corneal foreign bodies Common corneal foreign bodies can be divided into two categories: metallic foreign bodies and non-metallic foreign bodies. 1, metal foreign body: mostly seen in the knocking, cutting or grinding of metal objects spattered slag or fine pieces, such as iron filings, copper slag, nails, etc.. Metal foreign body is divided into two categories: magnetic metal foreign body and non-magnetic metal foreign body. 2, non-metallic foreign body: common in daily life, work in the environment flying foreign body (such as pesticides, dust), spattered debris (such as glass slag, gunpowder slag, coal chips, wall skin, debris, etc.); plant foreign body (such as bamboo sticks, chestnut thorns, cotton wool, willow, wood chips, bamboo chips, wheat mango, chaff, etc.), animal foreign body (such as hair, thorns, insects, etc.). In addition, corrosive liquids such as acids and alkalis used in factories or laboratories, as well as irritating liquids such as shampoo, make-up, gasoline, etc., can also become foreign bodies entering the eye. Second, the clinical manifestations of corneal foreign body The cornea is rich in sensory nerves and is one of the organs with the highest density of nerve endings distribution in the body. Therefore, the corneal sensation is very sensitive. When a corneal foreign body occurs, the foreign body itself will cause eye pain, tearing, foreign body sensation and other discomfort; if the foreign body damages the cornea, photophobia, blurred vision, eyelid spasm, afraid to open the eyes and other manifestations will also appear. If the corneal foreign body is not handled timely or improperly, it may cause keratitis, and in serious cases, it may cause corneal perforation and endophthalmitis, which may seriously affect vision and even lead to blindness. Therefore, once a corneal foreign body occurs, it must be removed as soon as possible, and then, according to whether it is accompanied by or other complications, the corresponding anti-inflammatory and symptomatic treatment is given. Third, the examination and treatment of corneal foreign body 1, examination: larger foreign body, the naked eye can be seen. In the hospital, the slit lamp microscope is usually used for examination. If the patient is afraid to open his eyes to affect the examination, he can give the affected eye some surface anesthetic before the examination, and then examine it when the patient can open his eyes. 2, treatment: due to the different severity of the condition of the part where the corneal foreign body is located, the treatment methods are different: (1) foreign body attached to the surface of the cornea: you can use a wet swab dipped in saline to gently wipe away the foreign body under surface anesthesia; or use saline to flush out the foreign body; (2) foreign body located in the superficial layer of the cornea: a professional is needed to remove the foreign body with a sterile foreign body needle or a fine needle under the slit lamp microscope (If there is a rust spot formation, try to scrape clean; multiple foreign bodies can be removed in stages); (3) foreign bodies located in the deep layer of the cornea or have partially penetrated the cornea into the anterior chamber: need to be surgically removed under the operating microscope (small inactive foreign bodies located in the deep layer of the cornea, such as broken glass, sand, plastic, etc., can be temporarily not removed); (4) acid, alkali and other corrosive liquids: to reduce acid, alkali on the cornea caused by (4) acid, alkali and other corrosive liquids: To reduce chemical damage to the cornea caused by acid and alkali, it is important to race against time, repeatedly and thoroughly rinse the eyes and try to wash out the chemicals in the conjunctival sac thoroughly. Then, go to the hospital as soon as possible, according to the specific situation, to give the appropriate treatment. Fourth, precautions 1, the eye into something, must not rub the eye with your hands to avoid secondary damage; 2, corneal foreign body removal should be strictly aseptic operation, otherwise there is a risk of septic corneal ulcer; 3, foreign body removal, timely administration of antibiotic drops or eye ointment to avoid corneal inflammation.