Kittens’ eyes get stuck shut for two main reasons: they haven’t yet reached the age when their eyelids naturally separate, or an infection is producing discharge that dries and seals the lids together. Knowing which situation you’re dealing with matters, because one is completely normal and the other can permanently damage a kitten’s vision if left untreated.
Normal Eyelid Development in Newborns
Kittens are born with their eyelids fused shut. This is by design. The eyes are still developing at birth, and the sealed lids protect delicate structures from light, debris, and bacteria during those first critical days. Over the first two weeks of life, the eyelids gradually separate on their own. Most kittens have fully open eyes by 10 to 14 days of age.
The timing varies slightly between individuals and even between litter mates. One eye sometimes opens a day or two before the other. As long as the lids look smooth and flat with no swelling, redness, or discharge, a kitten whose eyes are still sealed at day 10 is almost certainly fine. If a kitten reaches 14 days with no sign of the lids separating at all, that’s worth a closer look.
Infection: The Most Common Problem
When kittens’ eyes are stuck shut and shouldn’t be, infection is overwhelmingly the cause. Bacteria or viruses get into the space behind the still-fused eyelids, triggering inflammation and a buildup of pus. The discharge leaks out, dries along the lid margins, and essentially glues the eyes closed. This condition, called neonatal ophthalmia, can develop even before the eyes would normally open.
Several pathogens are responsible. Feline herpesvirus is the most common culprit and one that nearly every cat encounters at some point in its lifetime. The virus attacks the lining of the eyes, nose, and upper airways, causing tissue damage and intense inflammation. It’s particularly severe in young kittens, whose immune systems aren’t yet equipped to fight it off. Other causes include Chlamydophila felis (a bacterial infection that often starts in one eye before spreading to both), Mycoplasma, calicivirus, and various opportunistic bacteria that take hold when a kitten’s defenses are down.
Kittens born outdoors, in shelters, or to mothers with active respiratory infections face the highest risk. The pathogens spread through direct contact, shared bedding, and respiratory droplets in close quarters.
What the Discharge Tells You
The color and consistency of the gunk around a kitten’s eyes gives you useful information. Clear, watery discharge is common with mild viral infections or simple irritation. It can dry into a thin crust that lightly seals the lids.
Yellow or green discharge that’s thick and sticky signals a bacterial infection, either as the primary problem or layered on top of a viral one. This type of discharge accumulates faster, forms heavier crusts, and is more likely to seal the eyes completely shut. If you notice the discharge changing from clear to colored, or from thin to mucus-like, the infection is progressing.
Why Prompt Care Matters
A stuck-shut eye with infection behind it is not something that resolves on its own. The space between the sealed eyelids becomes a pocket where bacteria multiply rapidly, and the pus and inflammatory chemicals trapped inside attack the surface of the eye itself.
If the lids stay sealed while infection is present, the damage to the eye’s surface can be permanent. Vision may be significantly impaired or lost completely. One specific complication, called symblepharon, occurs when raw, ulcerated tissue on the inner eyelid or eye surface heals by fusing to adjacent tissue. The result is adhesions between the inner lining of the eyelid and the surface of the eye. These adhesions can restrict eye movement, block tear drainage, and reduce vision depending on where they form. Once symblepharon develops, it’s extremely difficult to correct.
Corneal ulcers are another serious risk. The cornea (the clear front surface of the eye) is vulnerable to damage from both the infection itself and the pressure of trapped discharge. Ulcers that go deep enough leave permanent scarring.
Signs That Need Immediate Attention
Some situations call for urgent veterinary care rather than a wait-and-see approach. Watch for these warning signs:
- Swelling or bulging around the eye area, which suggests significant pus buildup behind the lids
- Thick yellow or green discharge leaking from the lid margins
- A foul smell near the face
- Cloudiness or a bluish haze visible in any partially open eye
- Lethargy, hiding, or refusal to nurse, which suggest the infection has become systemic
- Pawing at the face or head tilting
A kitten that is withdrawn, irritable when touched near the face, or eating less than normal is telling you something is wrong beyond a mild eye issue. These behavioral changes and visible eye symptoms often point to the same underlying infection.
How to Safely Clean Crusty Eyes
For mild crusting with no swelling or colored discharge, gentle cleaning can help keep a kitten comfortable while you arrange veterinary care. Dampen a cotton ball with clean, lukewarm water and gently wipe from the inner corner of the eye outward. The warmth helps soften dried discharge so you can remove it without pulling or tugging on the delicate skin. Use a separate cotton ball for each eye to avoid spreading infection between them, and pat dry with a soft tissue.
Do not try to pry the eyelids open. Do not touch the eyeball itself. If the lids are swollen and clearly full of trapped discharge, a veterinarian needs to open them under controlled, sterile conditions. Forcing them apart at home risks tearing the tissue and introducing more bacteria.
What Veterinary Treatment Looks Like
When a kitten’s eyes are sealed shut by infection, a vet will gently separate the eyelids to drain the trapped discharge and flush the space clean. This is sometimes necessary even before the eyes would naturally open, because leaving the infection sealed inside is far more dangerous than opening the lids slightly early.
Treatment afterward typically involves topical antibiotic ointment applied directly to the eyes. Broad-spectrum options cover most bacterial infections. For infections caused by Chlamydophila or Mycoplasma specifically, tetracycline-based ointments are commonly used. If the kitten also has respiratory symptoms (sneezing, nasal congestion), oral antibiotics may be added. In herpesvirus cases, the virus itself can’t be eliminated, but controlling secondary bacterial infection and supporting the kitten’s immune system prevents the worst complications.
You’ll likely need to clean the kitten’s eyes and apply medication several times a day for one to two weeks. Keeping the lids free of crusting so the eyes can drain properly is just as important as the medication itself. Kittens with severe infections need rechecks to monitor for corneal damage or early signs of adhesion formation.
Kittens With Feline Herpesvirus
Because feline herpesvirus is the single most common cause of eye problems in kittens, it’s worth understanding what to expect. The virus destroys cells lining the eyes and respiratory tract, causing ulceration and heavy inflammation. In young kittens, this can mean severely swollen, crusted-shut eyes alongside sneezing, nasal discharge, and poor appetite.
Like human cold sores (caused by a related herpesvirus), feline herpesvirus never fully leaves the body. After the initial infection clears, the virus goes dormant and can reactivate during periods of stress, illness, or immune suppression. Recurrent flare-ups often show up as eye redness, squinting, or watery discharge. Kittens who had severe initial infections are more prone to lasting eye changes, including scarring or chronic tearing. Vaccination later in kittenhood doesn’t prevent infection but reduces the severity of symptoms significantly.