If the foreign body is too small to be seen by the naked eye and can only be found through a professional eye examination, the other reason is the patient’s subjective feeling that the foreign body will be felt when suffering from conjunctivitis, dry eye or keratitis. For foreign bodies that are difficult to see through the human eye, such as dust, mites, sand, detergents, hair, etc., professional eye examinations are usually used to clarify the type of foreign body, and for foreign bodies that enter the eye, fundus photography can be used to clearly diagnose the nature of the foreign body and to clearly observe the blood vessels in the eye around the foreign body. If there is a small foreign body, sterile saline can be used to flush the foreign body from the surface of the eye, and if necessary, the foreign body can be surgically removed. When a foreign body is found in the eye and cannot be found by the above means, it is considered to be an inflammatory reaction in the eye. In conjunctivitis, there is a foreign body sensation in the eye, a burning sensation and increased secretion; dry eye is a dry phenomenon of the conjunctival tissue itself, which also causes a foreign body sensation in the eye. The clinical manifestations of keratitis are foreign body sensation, blurred vision and tearing. For these inflammatory reactions caused by eye foreign body sensation should use some anti-microbial and inflammatory eye drops or drugs for sterilization and anti-inflammatory, usually can also supplement vitamin C, increase nutrition.