What it is: A raincoat for lashes—this long-wearing, waterproof mascara defines, curls, and lengthens lashes without smudging, clumping, or flaking. Wear it alone or layer over any Bobbi Brown mascara formula to make it instantly waterproof. Why it is different: The buildable formula creates natural to dramatic looks depending on how many coats are applied. The patented brush coats individual lashes evenly.