Preservative-Free Artificial Tears. I-DROP® PUR is highly effective at hydrating and lubricating the cornea. It provides advanced, long-lasting relief for mild to moderate dry eye disease and is contact lens compatible. I-DROP® PUR can be used in combination with lid massage and proper ocular hygiene to supplement additional lubrication. Instill one drop of I-DROP® PUR in each eye 2-3 times per day, or as directed by your eye care professional.