Lakme Kajal. Enough said. 

Although it may look like any generic eyeliner, kajal (specifically that marketed by Lakme cosmetics) is much softer in consistency, easier to intentionally smudge, more thickly applicable, and not as easily "eaten up" by our eye fluids. 

Kajal, the South Asian name for 'kohl,' was used by the ancient Egyptians to prevent eye ailments. It was also and is currently (in South Asia) used to protect the eyes from the harsh rays of the sun. In many South Asian cultures, today, kajal is worn to ward-off the "evil eye," which can be interpreted as any ill-wish of one upon another or even lustful eyes. This is interesting to note because of the opposite effect it might actually have or that it may actually be used to elicit in the Western world (i.e. the "smokey" or "sultry" 'bedroom eyes' that many women attempt to create with eyeliners and eyeshadows).