What is a dry eye?What are the main signs and symptoms of dry eye?How is dye eye diagnosed?What are some of the main medical treatments for dry eye?Have any supplements been studied for dry eye?How could diet affect dry eye?Are there any other treatments for dry eye?What causes dry eye?What are tears made out of?How can blocking tear ducts help with dry eyes?Is there a connection between caffeine intake and dry eyes?Are benzalkonium chloride-preserved eye drops harmful to eyes?