The truth about that yellow gunk in your eyes — and why it’s actually a sign you’re winning a battle in your sleep.
There’s nothing quite like getting into bed after a long, tiring day. You slip into your pillow, fall asleep, and let your body to recharge itself overnight. But then morning arrives, and before you’ve taken your first sip of coffee, you’re staring in the mirror, wondering what that crusty, yellow goop in the corner of your eyes is.
It’s something we’ve all experienced. That strange, sticky substance that appears when you’re asleep. Most of us just brush it away without thinking twice, but here’s the thing: that small crust collection is far more interesting than you realise.
The internet has been buzzing with a shocking conclusion, according to a new viral TikTok featuring neuroscientist Andrew Huberman: that gunk could be proof that your immune system fights (and wins) a microscopic war every night.
“If you’ve ever woken up with that kind of yellowy crust in your eyes,” Huberman informed you, “That’s actually dead bacteria that your eyes have successfully defeated during your night’s sleep.”
That’s accurate, those crusty little particles are like small souvenirs from a battle your body fought while you were asleep. When you wipe them away in the morning, you are essentially cleaning up the battlefield.
But what is really going on here?
During the day, blinking protects your eyes by keeping them moist and flushing out dust, dirt, and bacteria. Blinking, however, stops when you are asleep and your eyes are closed. This implies that the tear ducts go into maintenance mode, releasing a slow, continuous mixture of mucus, oils, and immune cells to maintain the eye surface healthy and protected.
Because there is no blinking to remove the buildup, it collects in the corners of your eyes. It can appear in a variety of ways, including crusty, sticky, thick, thin, clear, white, or slightly yellow, depending on what else is there. This is very normal, and there is usually no reason to be concerned.
This new information went viral on social media. One user quipped, “I refuse to lose even when I’m sleeping.” Another gleefully stated, “Starting the day with a victory.” Then there was the one who wrote, “When I was in kindergarten, I put them in my tea,” accompanied by a skull emoji. We’re choosing not to unpack that.
While regular ocular discharge is nothing to worry about, there are a few red flags to look for.
If you observe a lot of thick, yellow pus around your lashes, particularly if it is accompanied by redness, burning, itching, or gritty irritation, you may have conjunctivitis (also known as pink eye). Bacteria, viruses, or allergies can all cause this disease, which normally goes away within a week or two. But it’s highly contagious and unpleasant.
To treat mild conjunctivitis at home, the NHS suggests:
Wash your eyelids carefully with clean water (boil first, then cool, then use cotton pads – one for each eye).
Applying a cold, clean flannel as a compress to relieve burning or irritation.
Until symptoms improve, avoid wearing contact lenses or eye makeup.
Of course, if symptoms intensify or do not go away, it is preferable to consult a medical practitioner.
So, the next time you wake up with a small crust in your eyes, don’t be alarmed. Instead, acknowledge your accomplishments. Your immune system has worked hard all night, and what about that morning gunk? That proves you’re waking up like a winner.
