There are several possibilities for foreign body sensation in the eye: first, a tiny foreign body has entered the conjunctival sac of the eye, which can be relieved by turning the eyelid over and carefully examining the conjunctival sac and removing the foreign body. Second, inflammation of the ocular surface causes congestion and edema of the eyelid and conjunctiva. In this case, the congestion and edema cause unevenness of the conjunctival surface, and the contact between the eyelid and conjunctiva on the surface of the eye produces a foreign body sensation, which requires the use of medications to relieve the inflammation and the discomfort of the foreign body sensation. Third, relatively common is the presence of dry eye, the tear film in the conjunctival sac of the eye, which is supposed to play a lubricating role, has abnormal function in the case of dry eye, so it causes friction between the eyelids and the conjunctiva of the two layers of the eye, which also leads to foreign body sensation. In this case, it is necessary to use eye drops such as artificial tears to relieve the symptoms of dry eye and to restore the lubricating effect of the tear film in the eye, and in this way to achieve relief from foreign body sensation.