Mascara is supposed to last us about 3 to 4 months, but unfortunately most of us don't get that far. Mascara dries when air gets into the tube, so the best way to keep your mascara new is to NOT pump it. The pumping action pushes more air into the tube and you're left with dry and clumpy mascara.
If you notice your mascara is already drying up, you can get it back to its original form by simply applying 2 drops of Visine and giving it a quick shake. Voila! There you have it. New mascara! Read more at Listotic.com