Tears
A tear is a drop of clear saline fluid secreted by the lacrimal gland and diffused between the eye and eyelids. Actually, tears clean your eyes every time you blink. Tears keep your eyes moist, which is important for your vision. Tear glands produce tears, and tear ducts carry the tears from the glands to the surface of your eye. Problems with the tear system can include too many tears, too few tears, or problems with the tear ducts. Treatment of the problem depends on the cause.
Tears:
01 Tear Drainage System
02 Tear Layers
03 Punctal Plugs
Animation credit: American Academy of Ophthalmology