We believe that the possibility of feeling heat from the LED light or momentary pain during glue curing is extremely small. *There may be individual differences, so if a customer complains of discomfort, please discontinue use. *If trouble occurs, such as glue getting into the eyes, please rinse with large amounts of water. *If you experience any physical discomfort after having eyelash extensions applied, we recommend that you consult a medical specialist. *If the amount of glue applied is extremely large, you may feel heat, so please make sure to apply the proper amount of glue. Some people may feel glare from the LED light, so we ask that you apply Matsukaze LED UV Protect Eye Patch Sheets (50 pairs) to protect your eyes during the procedure. Also, in light of the irradiation time, temperature at the time of irradiation, and hair cycle, it is unlikely that damage will be caused to the eyelashes or that damage will accumulate.