three types of tears

So there is a part of the eye called the iris.It cries all of the time. It cries around ten ounces per day, that is about 30 gallons of tears per year!! It has special glands. One of them is called the Lacrimal glands, they make new tears for the iris. She also has special tubes called Lacrimal puncta, they take out the old tears. So you know when you look at onion, well it smells pretty good right? Well when you take the first layer off a chemical reaction happens converting the suffoxides that make is smell so greatinto sulfenic acid which then becomes an awful substance with a very, very long name, syn-Propanethial s-oxide it stings your iris and it starts crying like crazy. And there is also emotional tears like if someone died that you loved or some one you love is going away.

Iris usually cries basal tears it is surrounded by a thin coating of three layers. That protect it from dirt a debris.