The yellowish substance you find in the corners of your eyes when you wake up is known as “sleep” or eye discharge. This natural buildup is made of mucus, oils, dead skin cells, and dead bacteria. According to neuroscientist Andrew Huberman, this discharge is a sign that your body has been actively protecting your eyes overnight.
While you’re asleep, your eyes continue to produce moisture to stay healthy. However, since you’re not blinking, the usual drainage process slows down, allowing the materials to collect in the corners. The yellow tint often comes from the bacteria your eyes have neutralized during sleep.
This process is completely normal and part of your body’s daily cleaning routine. Think of it as a sign that your immune system is doing its job. Huberman even describes it as the “casualties of a war” your body fights to keep your eyes protected each night.
However, if the discharge becomes thick, greenish, or is accompanied by itching, redness, or burning, it could signal an infection like conjunctivitis (pink eye). In such cases, it’s best to seek medical advice to ensure your eyes stay healthy.