My dog Indy is a boxer mastiff mix. We named him after the scene in Indiana Jones and the Last Crusade when Indiana’s dad, played by Sean Connery, was pointing out that Jones’ actual name was “Henry Jones Junior. We named the dog Indiana.” So we named the dog Indiana too! He’s a huge hunk of a dog at 65 pounds, but it’s balanced out by him being sweet tempered and a total snuggle-bug. We rescued him nearly a year ago from Boxer Luv Rescue (support them, they are awesome!). He was found on the border of Arizona and Mexico with a skin condition (likely mange) and entropion in both eyes. This entropion causes his the eyelid to roll inward and irritate the eye, so he had surgeries on both eyes before we got him to try to fix this problem. the surgery didn’t fix it 100%, so we use some lubricating gel to help soothe his eye when it’s needed. The only way we know there’s something wrong with his eyes is that he wakes up every morning with enormous eye boogers! I’m not talking about the normal crusties that you have in your eye and quickly pick away each morning (my family used to call them “sleepy seeds”). I’m talking about globs and globs of gunk that I carefully wipe out every morning and sometimes again in the afternoon with a wet washcloth.
Because of my now intimate and frequent involvement with eye boogers, I started thinking about what these actually are, what they are made of, and why they are sometimes crusty, sometimes gunky and sometimes just plain disgusting. To answer these most important questions, I went and did some research!
Let’s start by talking about what is in your eyes besides your eyeballs. Your eyes are protected by the “tear film,” which is made up of an outer oily layer, a middle water layer, and an internal mucus layer. This is actually really cool if you think about it. Imagine you have a cup of water with a thin layer of oil over it. The oil will slow down evaporation of the water just like the oily layer of the tear film. It will also prevent stuff from getting into the water. These are two of the tear film’s major jobs: keep the eye moist and remove debris, which occurs while blinking. The oil also acts as a lubricant to make blinking your eyes easier. The mucus layer, closest to the eye, also helps prevent debris from getting to the eye because it’s super sticky (think of it as the flypaper of the eye) and traps foreign particles so that they can be removed from the eye by tears. The tear film also helps make your vision clear by making the surface of the eye smooth it refracts light properly, and it protects against infection (because it contains antibacterial substances).
The official name for eye boogers is “rheum“. More specifically, eye boogers are one type of rheum, which is the discharge that comes from the eyes, nose and mouth during sleep. This discharge is made up of mucus, oil, dead skin cells and other debris (like dust) – so in other words, the discharge is made up of that tear film that protects your eyes throughout the day. So why does it gunk up at night? Because at night, you aren’t blinking and the rheum isn’t being washed away by your tears. Instead the rheum collects in the eye and crust/gunk up in the corner of the eye.
Why are eye boogers sometimes crusty and other times (like in Indy’s case) completely goopy? The wetness or dryness of the eye boogers can be different depending on how much of the moisture has evaporated from the tear film. So with Indy, his eyes have more discharge because of the eye irritation and this accumulates into a goopy mess because the water isn’t evaporating from the rheum when he sleeps.
Even though eye boogers change from night to night, there are medical reasons why you may have more or less eye boogers. These changes in color or consistency could be an indication of a problem – such as dry eyes, an eye infection, a clogged tear duct, allergies or other eye irritation. So if your eyes are crusted shut or if your eye boogers are green, you can first tell your friends how eye boogers are made, and then get yourself to a doctor.
When I talked to my Mom about this post (she gets sneak previews because she’s my mom), her main question was whether dog eye boogers and people eye boogers are the same. From some limited research, I found that dogs also have a tear film composed of the same layers the human’s have and has the same purpose. Different parts of the dog eye anatomy create these layers compared to humans, but otherwise, it seems like it’s similar in concept. There are lots of articles about dog eye boogers (usually officially referred to as “eye discharge”) and many of the same problems, plus a few others, affect both dogs and people to cause abnormal eye boogers. The same advice applies to people and dogs – if there’s more eye boogers or they start changing color, bring the dog to the vet to check it out.
Some of the other articles that have covered this extremely important topic:
Are yours crusty or wet? The truth behind eye boogers (ew)
Why do we get sleep in our eyes?
Where do eye boogers come from?
What are ‘eye crusties’ made of?