Iris is very sensitive.

Iris 非常敏感。

So much that she is always in tears.

敏感到她總是在流淚。

She cries when she's sad, when she's happy, and even tears up when things just get to her.

當她難過的時候她會哭，當她高興的時候她會哭， 甚至當有東西使她煩惱的時候，她也會哭。

She has special lacrimal glands to make new tears and special tubes, called lacrimal puncta, to drain old ones away.

她有個特殊的淚腺能製造新的眼淚還有特殊的管子，叫做淚點，會把舊的眼淚排走。

And she cries so much that she goes through ten ounces of tears per day.

她太愛哭了，她每天會哭出十盎司的眼淚。

Thirty gallons a year!

一整年有三十加侖！

In fact, if you look closely, you'll see that she's crying a little bit all the time.

事實上，如果你靠近點看，你會看見她的眼睛總是有點濕濕的。

The basal tears that Iris constantly produces form a thin coating of three layers that cover her and keep dirt and debris away.

Iris 持續分泌的基礎眼淚形成了一個三層的薄膜覆蓋住她，避免灰塵和碎片接近。

Right next to Iris is the mucus layer, which keeps the whole thing fastened to her.

緊靠著 Iris 的是黏液層，黏液層能讓整團淚滴緊貼著她。

On top of it is the aqueous layer,

在它的上面是淚水層，

which keeps Iris hydrated, repels invasive bacteria, and protects her skin, or cornea, from damage.

它讓 Iris 保持濕潤，擊退入侵的細菌， 並保護她的薄層或角膜，使其免於傷害。

And finally, there is the lipid layer,

而最後，是油脂層，

an oily outer film that keeps the surface smooth for Iris to see through, and prevents the other layers from evaporating.

油性的外膜可以保持表面平滑，讓 Iris 可以看得清楚， 並避免其他膜層的水份蒸發。

Normally, Iris goes about her day without really noticing the basal tears doing their thing.

正常來講，Iris 一整天都不會注意到基礎眼淚的作用。

That's kind of their whole point.

基礎眼淚大概就是這麼回事。

But one day, she meets a girl named Onion.

但是有一天，她遇到了一個叫做洋蔥的女孩。

Iris is immediately smitten.

Iris 馬上就被迷住了。

Onion looks gorgeous in her bright purple jacket, and she smells terrific.

洋蔥妹穿著亮紫色的夾克看起來很華麗，而且她聞起來非常香。

So, Iris invites Onion to her house for dinner.

所以，Iris 邀請洋蔥妹到她家吃晚餐。

But when she comes in and takes off her jacket, something terrible happens.

但是當她進來並脫下了她的外套時，可怕的事情發生了。

You see, when Onion's jacket is removed, a chemical reaction happens,

你看，當洋蔥妹的外套脫下，就會發生了一種化學反應，

converting the sulfoxides that make her smell so great into sulfenic acid,

讓洋蔥妹聞起來很香的化合物亞碸轉換為次硫磺，

which then becomes a nasty substance with a long name:

而後又變成一種令人難受、有著落落長名字的物質：

syn-Propanethial S-oxide.

順式-丙硫醛-S-氧化物。

The gas stings Iris, and suddenly, she can't help it, she starts weeping uncontrollably.

這個氣體刺激著 Iris，突然間，她忍不住了，她開始不能控制地流淚。

These reflex tears are different from the basal tears that Iris is used to.

這些反射性眼淚跟 Iris 平常流的基礎眼淚不一樣。

Because they're designed to wash away harmful substances, or particles,

因為它們是被設計用來清洗有害的物質，或顆粒，

they're released in much larger amounts,

它們釋放的量更大，

and their aqueous layer contains more antibodies to stop any microorganisms that may be trying to get in, as well.

淚水層也包含更多的抗體去阻止任何試圖進入的微生物。

Both Iris and Onion are devastated.

Iris 和洋蔥妹都傷心欲絕。

They know they can't continue their relationship if Iris is going to hurt and cry every time Onion takes off her jacket.

她們知道，要是每次洋蔥妹脫掉她的外套時 Iris 都會受傷並且哭泣，她們就無法繼續她們的關係。

So, they decide to break up.

所以，她們決定分手。

As Onion walks out the door, Iris stops crying, and immediately starts again.

當洋蔥妹一踏出門，Iris 就停止哭泣了， 但馬上又再次流淚。

Only now, she's not crying reflex tears but emotional tears.

只有現在，她不是流出反射性眼淚，而是情感性眼淚。

When someone is either too sad or too happy, it feels like a loss of control, which can be dangerous.

當某人太難過或是太高興時，會感覺像是失控，而這可能會導致危險發生。

So, emotional tears are sent in to stabilize the mood as quickly as possible, along with other physical reactions, such as an increased heart rate and slower breathing.

所以，情感性眼淚被派去快速穩定這樣的情緒，伴隨其他身體反應，像是加快心跳和減緩呼吸。

But scientists still aren't sure exactly how or why the tears themselves are helpful.

但是科學家仍不確定眼淚究竟如何提供幫助以及為何會有幫助。

They may be a social mechanism to elicit sympathy or show submission.

眼淚可能是一種社交機制用以引起同情或示弱。

But some studies have also found that emotional tears contain higher levels of stress hormones, such as ACTH and enkephalin, an endorphin and natural pain killer.

但是有一些研究也發現情感性眼淚有著更高層次的壓力賀爾蒙，像是促腎上腺皮質刺激素（Adrenocorticotropic hormone）和腦啡，一種內啡肽和天然的止痛劑。

In this case, emotional tears are also directly calming Iris down, as well as signaling her emotional state to others.

在這種情況下，情感性眼淚也會直接使 Iris 平靜下來，並且發出她的情緒狀態訊號給其他人。

Sorry things didn't work out with Onion, Iris.

很遺憾和洋蔥妹的感情失敗了，Iris。

But don't worry.

但是別擔心。

As long as you have all three kinds of tears working to keep you balanced and healthy, it will get better.

只要妳擁有三種眼淚幫助你保持平靜和健康，一切都會變好的。

You'll see.

妳會懂的。