An under-eye roll-on is a skincare product designed to target dark circles, puffiness, and fine lines around the eyes. It typically comes in a small, portable tube with a rolling applicator, allowing for easy and precise application. The roll-on is often infused with ingredients like caffeine, hyaluronic acid, and vitamins, which help to revitalize and brighten the under-eye area. The cooling effect of the metal roller also aids in reducing swelling and refreshing tired eyes, making it an ideal addition to any skincare routine for a more awake and youthful appearance.