Decreased corneal perception causes reduced transients and affects tear film reconstruction. On the one hand, decreased corneal perception decreases the nerve impulses transmitted from the cornea to the brain system via the reflex arc, resulting in a decrease in nerve impulses transmitted from the brain down to the lacrimal gland and causing a decrease in basal tear secretion. On the other hand, when corneal perception is diminished, the corresponding transient frequency decreases because transient frequency is positively correlated with corneal perception, and transient is the basis of tear film reconstruction: each time you blink, the transient action distributes tear mucin evenly on the corneal surface, and also distributes the aqueous and lipid layers evenly on the corneal surface, completing tear film reconstruction. A decrease in the number of blinks leads to enhanced tear evaporation, which affects the uniform distribution of mucin on the ocular surface, thus preventing the aqueous and lipid layers from adhering well and affecting tear film reconstruction. Reduced corneal perception is a clinical symptom of exposure keratitis. Exposure keratitis commonly occurs in a variety of lesions with incomplete lid closure, resulting in impaired corneal exposure and transient eye movements, and corneal epithelial damage due to the inability of tears to wet the cornea properly. How is reduced corneal perception diagnosed? Combined with the medical history, general corneal visualization, photoplethysmography and Placido disc examination, and corneal staining are chosen to examine the corneal lesions. Due to exposure of the corneal surface, tear evaporation is too rapid and the corneal epithelium is dry, blurred, necrotic, detached, ulcerated, or corneal epithelial keratosis with stromal infiltrative clouding. If the degree of lid closure is mild and only a third or less of the lid is exposed due to the upward rotation of the eyeball when the eye is closed (Bell’s phenomenon), the corneal damage is limited to that part of the lid, which is less perceptive and cannot reflexively block foreign body attacks, making it vulnerable to service and even secondary bacterial and fungal infections. In the case of incomplete lid closure, the exposed corneal surface becomes dry due to accelerated evaporation of fluid, resulting in severe infiltration and ulceration, and there is no secondary infection, generally only a grayish tone, no drastic changes, and no suppuration. Patients with this disease are extremely uncomfortable due to corneal exposure. It is important to prevent corneal dryness at all times while treating the primary disease, such as making sure to apply plenty of antibacterial eye ointment before sleeping to prevent corneal dryness and infection. If necessary, the doctor can temporarily suture the eyelid, leaving a slit in the center of the lid to see while keeping the corneal conjunctiva moist.