When you yawn, the muscles around your eyes squeeze and gently press on your tear (lacrimal) glands and tear drainage system, which can push out extra tears and make your eyes water. This is a normal reflex and usually not a sign of any problem.

How yawning makes eyes water

  • The wide stretch of a yawn activates many facial muscles, including those around the eyes. This can compress the lacrimal glands, causing them to release more tears than usual.
  • At the same time, the squeeze can briefly disrupt tear drainage through the tear ducts, so tears pool on the eye surface and overflow as “watery eyes.”

Reflex and eye protection

  • Yawning often comes when you are tired, and tired or slightly dry eyes trigger reflex tearing to keep the cornea protected and lubricated.
  • The combination of eye surface dryness, facial muscle squeeze, and brief drainage disruption makes the normal tear film “overflow,” so it looks like you are tearing up.

Is it ever a problem?

  • For most people, watery eyes with yawning are completely harmless and just a quirk of how the tear system is built.
  • If you notice constant tearing, eye pain, strong dryness, or vision changes even when you are not yawning, an eye doctor should check for dry eye, blocked tear ducts, or other conditions.

TL;DR: Our eyes water when we yawn because the yawn squeezes eye-area muscles, briefly presses on tear glands and ducts, and often happens when eyes are tired or a bit dry, so the normal tear film overflows as visible tears.

Information gathered from public forums or data available on the internet and portrayed here.