The lacrimal sacs (pictured to the right) are hollow oval
lacrimal canals are curved, tube shaped structures that
drain tears from the eyes and carry them to the lacrimal
Each eye has a lacrimal sac for tears to drain into. Flat
muscles that cover the lacrimal sacs squeeze and
release them during blinking. This helps produce a
suction effect that draws away extra tears when
blinking. This is why people blink when they cry.
The upper end of the lacrimal sac is round and closed. The lower part of the lacrimal sac
connects to the nasolacrimal ducts and forms the upper widened part of that structure.
Nasolacrimal ducts are tube shaped areas below the lacrimal sac that carry tears down
through the bone, leading to an opening in the nose.
For a description of the other items in the picture above, see the entry for lacrimal
apparatus. The lacrimal apparatus is the system in the body that produces and drains
tears. The lacrimal sacs can be pictured by a technique known as dacrocystography in
which a contrast material is injected into the lacrimal sac area and an X-ray is taken.