Jul 11, 2025

Understanding Eyelash Structure: A Simple Guide

"I use an eyelash serum, but how do eyelashes actually work?" "I want to keep my lashes healthier!"

Do you find yourself asking these questions?

While we see our eyelashes every day, they have a surprisingly complex and fascinating structure. Understanding how they work is the first step towards effective lash care and achieving more captivating eyes.

This article will clearly explain everything from the basic structure of eyelashes to their internal mechanisms, delving into aspects you might not know.

The Basic Structure of Eyelashes: The Seen and Unseen Parts

Eyelashes are broadly divided into two main parts: the "hair shaft," which is visible above the skin surface, and the "hair root," which is hidden beneath the skin.

[Image showing the overall structure of an eyelash]

Hair Shaft: This is the part we typically recognize as the eyelash.
Hair Root: Embedded within the skin and invisible to the naked eye, this is the crucial part where eyelashes are made and grow.

The Eyelash "Factory": The Hair Bulb

At the very bottom of the hair root is a rounded, bulb-like structure called the "hair bulb." This area houses the essential tissues responsible for creating eyelashes.

Dermal Papilla: Located at the base of the lash, it receives nutrients from capillaries and stimulates lash growth.
Matrix Cells (Hair Mother Cells): These parent cells receive nutrients from the dermal papilla and divide repeatedly to form the main body of the eyelash.
Melanocytes: These cells produce melanin pigment, which gives eyelashes their color.
Capillaries: Tiny blood vessels that deliver the necessary nutrients to the matrix cells.
Sebaceous Gland: Secretes sebum (oil) to give lashes shine and protect them from dryness and external irritants.

In essence, the hair bulb functions like a "factory" where eyelashes are born and nurtured.

What's Inside an Eyelash? Exploring the 3-Layer Structure

If you were to magnify a single eyelash (the hair shaft), you'd find it's actually composed of three distinct layers.

Medulla: The innermost core of the eyelash. It's made of proteins and lipids, is soft, and contains air pockets. Its presence varies depending on the thickness of the hair; it might be minimal or absent in fine or vellus hair. It's thought to be related to moisture retention and elasticity.
Cortex: This layer makes up the bulk of the eyelash (about 85-90%). It consists of strong keratin fibers (fibrils) and a matrix that binds them together. The cortex contains abundant melanin pigment, primarily determining the lash color. It also plays a role in retaining moisture and maintaining flexibility.
Cuticle: The outermost layer that covers the eyelash. It consists of 6-8 overlapping layers of hard, transparent, scale-like keratin cells that protect the inner layers. The shine of the eyelash comes from the cuticle. However, it's vulnerable to friction and can be easily damaged or stripped away by harsh cleansing or rubbing. Damaged cuticles lead to a loss of shine and smoothness, and in severe cases, can cause breakage.

Summary: Understand Your Eyelash Structure for Proper Care

We've taken a detailed look at the basic structure and internal workings of eyelashes.

Eyelashes consist of a "hair shaft" and a "hair root."
In the "hair bulb" at the root, matrix cells divide to create the lash.
The eyelash shaft has a three-layer structure: "medulla," "cortex," and "cuticle."
The "cuticle" protects the inner layers and provides shine but is susceptible to friction.

By understanding the structure of your eyelashes, you can better appreciate why gentle cleansing and moisturizing are so important. Let's nurture beautiful, healthy lashes through proper daily care.