It's possible to get swollen eyes after using eyelash extensions actually. There are a few reasons to give rise to this symptom. One of them is, maybe your skin is allergy to the brand of eyelash that you used. You can choose another brand of eyelash. However, if you still have this problem after trying various brands of eyelash, I advise you not to use eyelash anymore because your skin belongs to allergic skin. The other reason is infection. As we know, many eyelash extensions are made of inferior animal hairs or even polluted by bacteria. As you rub your eyes, these bacteria will immerse into your eyes silently. Therefore, you'd better keep away from eyelash extensions for a period of time, and you might feel changes. Thanks for reading.