Some babies are born without tear ducts working properly and need special drops to maintain the eyes moist to prevent vision problems that results from lack of moisture within eyes.
Since the lens is rigid, it irritate the if you will not find enough tears under they. http://can-Eng.de/__media__/js/netsoltrademark.php?d=Www.Opticaljournal.com%2Fnew-study-on-sjogrensmeibomian-dysfunctiondry-eyes%2F