Sudden pain in one eye when blinking is usually caused by dust, foreign objects such as eyelashes, trauma, or inversion of the eyelid. It is also possible to have blepharitis, conjunctivitis, dry eye, etc. It is recommended that you seek medical attention to identify the cause and provide targeted treatment.1. Blepharitis, or wheals, is an acute purulent inflammation usually caused by Staphylococcus aureus infection. The main symptoms are redness, swelling, pain, and other signs of acute inflammation in the affected area. If the patient has the disease in one eye, he or she may experience sudden pain in one eye upon blinking, and may develop pustules and tearing. Patients can promote blood circulation in the eye by applying local heat to relieve the symptoms. If pustules appear, antibiotic eye drops, such as levofloxacin hydrochloride eye drops and norfloxacin eye drops, can be applied under the guidance of a medical professional. If the symptoms are not relieved, you can also use ultrashort wave physical therapy, incision and drainage for treatment; 2. Conjunctivitis: usually due to physical stimulation, chemical stimulation, infection, and the existence of their own immune pathology, the main symptoms are redness, swelling, itching, dryness, blinking pain, photophobia, tearing, foreign body sensation and increased secretions in the diseased side of the eye. Patients need to be treated according to the specific cause of the disease. In addition to treating their original disease, antibacterial drugs and antiviral eye drops can be used topically to reduce inflammation. Such as norfloxacin eye drops, tobramycin eye drops, etc. In order to avoid further development of inflammation, leading to further damage to visual function and the eye. If the symptoms are severe, systemic medication can be administered, usually without surgery; 3. Dry eye: dry eye is usually caused by abnormal tear composition, insufficient tear secretion or excessive evaporation in patients, and the main symptoms are dry eyes, fatigue, foreign body sensation, and may also be accompanied by photophobia, pain, and a burning sensation, which can lead to symptoms such as pain when the patient suddenly blinks unilaterally. If left untreated, the cornea may even be damaged, leading to serious complications such as infection, corneal perforation and corneal ulceration, which can affect the patient’s vision. Patients in this category can help relieve eye discomfort by applying artificial tears and antibiotic eye ointment, and by avoiding prolonged computer and cell phone viewing in daily life to eliminate the triggers of dry eye. In addition, blepharoplasty can be used to treat the condition if it is caused by incomplete eyelid closure.