Eyelash extensions can be caused by soft tissue damage, conjunctivitis, blepharitis and other diseases, as well as keratitis and other diseases. 1. Soft tissue injury: When patients have eyelash extensions, if the operator is too violent in the eyelash extensions, resulting in soft tissue injury to the eye, patients will have swollen eyes. 2. Conjunctivitis: Conjunctivitis has many causes, including bacterial, viral and other pathogenic infections, immune lesions and other factors. The main symptoms of patients are redness, dryness, itchy eyes and congestion. Conjunctivitis can occur if the patient has an improperly sterilized eyelash extension that leads to a bacterial infection or if the patient is allergic to the glue and the eyelashes. 3. Blepharitis: Blepharitis is mainly caused by bacterial infection, and the patient’s main symptoms are redness, swelling, pain, fever and hard nodules in the eyes. If a patient has a bacterial infection when getting eyelash extensions, it can lead to blepharitis, resulting in swollen eyes. 4. Other: Keratitis, dacryoadenitis and other diseases can also lead to the phenomenon of swollen eyes in patients with eyelash extensions. Patients with swollen eyes from eyelash extensions should seek medical attention in a timely manner and follow the doctor’s instructions.