WEBVTT

99:59:59.999 --> 99:59:59.999
Our story is about a girl named Iris.

99:59:59.999 --> 99:59:59.999
Iris is very sensitive.

99:59:59.999 --> 99:59:59.999
So much that she is always in tears.

99:59:59.999 --> 99:59:59.999
She cries when she's sad,

99:59:59.999 --> 99:59:59.999
when she's happy,

99:59:59.999 --> 99:59:59.999
and even tears up when things just get to her.

99:59:59.999 --> 99:59:59.999
She has special lacrimal glands to make new tears

99:59:59.999 --> 99:59:59.999
and special tubes, called lacrimal puncta,

99:59:59.999 --> 99:59:59.999
to drain old ones away.

99:59:59.999 --> 99:59:59.999
And she cries so much that she goes through

99:59:59.999 --> 99:59:59.999
ten ounces of tears per day,

99:59:59.999 --> 99:59:59.999
30 gallons a year!

99:59:59.999 --> 99:59:59.999
In fact, if you look closely,

99:59:59.999 --> 99:59:59.999
you'll see that she's crying a little bit all the time.

99:59:59.999 --> 99:59:59.999
The basal tears that Iris constantly produces

99:59:59.999 --> 99:59:59.999
form a thin coating of three layers,

99:59:59.999 --> 99:59:59.999
that cover her and keep dirt and debris away.

99:59:59.999 --> 99:59:59.999
Right next to Iris is the mucus layer,

99:59:59.999 --> 99:59:59.999
which keeps the whole thing fastened to her.