This has got to be the best eyeliner for inside my eyes that I have ever used!
My eyes are pretty sensitive and water a lot so lining my inner lower eye usually leaves me with a heavy panda eye and no liner. However this product is extremely long lasting and did not smudge at all (even when I was practically crying).
You need to buy an applicator brush with it (MAC has some great ones).

Gives a strong, bold look that will really highlight your eyes.