This can happen especially in the winter, due to the heating that dries out the air. The vapors from the glue are attracted to moisture and when the air is in the room, the vapors are redirected to the eyes, nose and mouth, which causes irritation. Therefore, we recommend that you humidify the air in the salon regularly. The reason for the reaction to the glue may also be that the client has his eye closed while applying the lashes. Thus, vapors can get into the eye and cause irritation. In this case, it is a chemical burn – a red line in the eye, which is not an allergy. Always make sure your client has a well-closed eye. You also need to make sure that your customer is not sensitive to any other ingredient in other products – cleansers, paints, eye protection, etc. Always read what ingredients they contain and consult with the client about her allergies. Sometimes, even if you’ve done all the rules, customers can develop an allergy to any of the ingredients over time. Refer them to a doctor.