“In the first few months, a parent may note one [baby’s] eye crusted shut in the morning without any redness,” says Dr. Lisa Lewis, MD, a board certified pediatrician in Fort Worth, Texas, and author of “Feed the Baby Hummus, Pediatrician-Backed Secrets from Cultures Around the World.”
“Usually, the crusty eye is due to a blocked tear duct,” continues Dr. Lewis. “A blocked tear duct causes the eye to tear more.
“Parents will note dried tears in the form of crusting after sleeping overnight or a nap.
“If both eyes are crusting all day or the crusted eye is associated with redness, this could be an indication of infection. In this case, have the baby examined by a doctor.”
The process that causes a baby’s eye to be crusted shut every morning is the same process that causes many adults to awaken with “crust and gunk” in their eye.
The eyes naturally form tears or fluid to keep the eyeball surface lubricated.
Tear ducts, called puncta (punctum for singular), allow drainage of the natural tears.
This is normally balanced, so that the eyes do not dry out or become too watery.
If there’s a plug in a punctum, fewer of the tears will get drained, thereby causing a buildup of the fluid on the eye – leading to crusty gunk in the eye and on the lid. In a baby, this is more likely to cause the lids to be crusted closed in the morning upon waking.