Meibomian glands: your eyes' oil factories
When the oil goes wrong, it's the most common cause of dry eye.
- 01Dry eyes? It's not just a lack of water
- 02Meibomian glands: your eyes' oil factories
- 03Why won't my tears stay put?
- 04Why does dry eye keep coming back?
- 05Health conditions that can dry your eyes
- 06Everyday habits that quietly feed dry eye
- 07“It's just dry eyes”? It's not that simple
- 08Managing dry eye: from home to clinic
- 09In-clinic treatment: IPL, RF & expression
Where are the meibomian glands?
Part 02 · 01Inside the tarsal plate of each eyelid
Around 25–40 in the upper lid and 20–30 in the lower.
Openings sit on the lid margin, behind the lashes
A row of tiny openings, hard to see with the naked eye.
Blinking squeezes the oil out
The lid muscles push oil onto the tear film with each blink.
How is the oil made?
Part 02 · 02Holocrine secretion
Cells fill with lipid, then break down entirely into oil.
Mostly lipids
Mainly wax and cholesterol esters, plus some polar lipids.
Healthy meibum is clear and fluid
It melts at eyelid temperature and spreads with each blink.
A good oil layer does three jobs
Part 02 · 03Slows evaporation
It sits over the watery layer like a lid, reducing water loss.
Keeps the tear film smooth and stable
The film lasts longer after each blink, for clearer, steadier vision.
Seals the lid margin
It stops tears spilling over, and helps seal the lids when they close.
When the glands get ‘blocked’: MGD
Part 02 · 04Blocked, keratinised openings
Oil can't get out, so it builds up and thickens.
Oil turns thick and cloudy
From ‘olive oil’ to ‘toothpaste’: it no longer spreads.
Long-term blockage leads to atrophy
Glands shorten or disappear, and rarely grow back.
How the tear film fails
Part 02 · 05Tear film drawn thousands of times thicker than real. Not to scale.
What poor oil does to the tear film
Part 02 · 06A thin, patchy oil layer
Tears evaporate faster and the film breaks up early.
Tears turn ‘salty’
Raised osmolarity irritates and inflames the surface.
Surface damage
Dryness, burning, grittiness, and vision that comes and goes.
Signs your oil may be the problem
Part 02 · 07Dry, burning, gritty eyes
Often worse in the evening, after screen time, or in air-con.
Vision that comes and goes
It clears after a few blinks, then blurs again.
Watery eyes, surprisingly
An irritated surface triggers reflex tearing: dry eyes that water.
Sticky lids, red lid margins
Lid margins may look red or thickened, or have discharge.
Key takeaways
Part 02- 01Meibomian glands sit inside the lids and make the tear film's oil
- 02Thick oil and blocked openings mean MGD
- 03Poor oil → faster evaporation → saltier tears → inflammation
Book an eye surface assessment.
Eyes that often feel dry or gritty, or vision that comes and goes? Find out which type you have and what’s driving it.
General health information only, not personal advice. Everyone’s eyes are different. An optometrist or doctor should examine you before any treatment is decided.