What is the small hole in the lower eyelid for?

There is a small hole in the lower eyelid, which is a normal physiological phenomenon. If you gently pull the upper and lower eyelids up and down, you can observe this small hole. This small hole is called the tear point. It has the function of channeling tears. If it is blocked, it will often lead to blockage of the tear glands and even cause some more serious diseases. When you have a cold, you often feel your nose swelling, which can cause your tear ducts to become blocked.

What is the small hole in the lower eyelid for?

If we gently pull the upper and lower eyelids up and down, we will clearly see that there is a small hole at the upper and lower corners of the eyes near the nose, which is medically called the tear point. It is very small, with a diameter of only 0.2-0.3 mm, but don't underestimate it, it plays a big role. It, together with the small tear duct, lacrimal sac and nasolacrimal duct leading to the nasal cavity, forms a sewer-like tear duct that guides the tears secreted by the lacrimal glands into the nasal cavity. Without it, the tears secreted by the tear glands cannot be channeled into the nasal cavity, and we will inevitably shed tears there all day long.

The role of tear points

Someone must ask, since the tear ducts formed by tear points can channel tears, then why do so many tears flow out when we are mixed with sadness or joy?

We know that normally the secretion and drainage of tears are balanced, so people do not feel tears. However, when people shed a lot of tears due to mixed feelings of sadness or joy, the balancing effect is lost, and the tear points are unable to drain such a large amount of tears to the tear ducts, so they have to let them flow out. Everyone must have had this experience: when it rains lightly, the sewers on the road are unobstructed. When it rains heavily, the sewers are unable to drain such a large amount of rainwater, causing temporary water accumulation on the road. It is the same principle.

In addition, if the position of the tear points changes, or if you catch a cold, the tear ducts may be blocked due to compression of the nose due to swelling, or if the tear ducts become inflamed, even though the amount of tear secretion is normal, tearing may occur because the tear points and tear ducts lose their drainage function.