It's not unusual for newly applied eyelash extensions to come off the day of application. This is because the extensions are placed 1-2 mm from the lash line, and your natural eyelashes are constantly growing. To prevent this, gently comb your lashes from the middle to the tip closest to your filling appointment. If the adhesive hardens before the extension adheres to the natural lashes, there will be poor adhesion and the lashes will eventually peel off after a day or two.
Additionally, the length of eyelash extensions depends on multiple factors, including the degree of eyelash care by customers. Make sure that you use makeup that does not contain oil and is safe for eyelash extensions. You may also notice that one eye seems to come off faster than the other, simply because you now have older eyelash extensions and natural eyelashes in that other eye. It's important to understand that eyelash loss is a normal part of the growth cycle.
Oil in your shampoo and conditioner can also break the eyelash extension adhesive. To maintain a more natural and professional look, invest in a contoured sleep mask or 3D mascara for eyelash extensions and use a safe cleanser for eyelash extensions with cleansing brushes.