Why do cats slow blink at you?
A slow blink is a relaxed, friendly signal. When a cat looks at you, narrows its eyes and closes them slowly, it is showing that it feels calm and comfortable. A 2020 study in Scientific Reports found that cats respond in kind: they narrowed their eyes more when their owners slow blinked at them, and were more likely to approach an unfamiliar person who slow blinked than one with a neutral face.
What a slow blink looks like
The researchers behind the main study on this behavior describe the "slow blink sequence" as a series of half blinks followed either by a prolonged narrowing of the eyes or by closing the eyes. To us it looks like a sleepy, contented squint, often while the cat is looking toward you. Cats Protection lists slow blinking among the clearest signs of a happy cat, alongside an upright tail and relaxed, forward facing ears.
What the research found
The study by Tasmin Humphrey and colleagues, with Professor Karen McComb as senior author, ran two experiments in cats' own homes:
- Owners and their cats. In the first experiment, 21 cats from 14 households were filmed while their owners either slow blinked at them or sat without interacting. Cats produced more half blinks and eye narrowing when their owners slow blinked.
- Strangers and cats. In the second experiment, with cats from 8 households, a researcher the cats had never met either slow blinked or kept a neutral expression, then held out a hand. Cats were more likely to approach the researcher's hand after the slow blink.
The authors concluded that slow blink sequences may work as a form of positive emotional communication between cats and humans. Eye narrowing is linked with positive emotion in several other species too.
What the research does not show
It is tempting to call a slow blink a "cat kiss" or say it means "I love you". The study does not go that far. It shows that slow blinking is associated with a relaxed, positive state and makes cats more willing to approach, not that it carries a specific message. It may have developed because, among cats, an unbroken stare can feel threatening, so narrowing the eyes signals the opposite. That idea is plausible but has not been proven.
How to slow blink at a cat
- Sit or crouch at a comfortable distance and let the cat see you. Do not loom over it.
- Look toward the cat with a soft gaze rather than a hard stare.
- Narrow your eyes slowly, as if smiling with your eyes, then close them for a second or two.
- Open your eyes and look slightly away, then repeat once or twice.
- If the cat narrows its eyes or slow blinks back, offer a hand at the cat's level and let it choose whether to come over.
It is a useful way to greet a shy cat, a new rescue or a cat at a friend's house, because it lets the cat decide what happens next. That fits the AAFP and ISFM principle that cats prefer predictable, gentle social contact on their own terms (see cat care basics).
When eye squinting is not a slow blink
A happy slow blink happens with a relaxed body and comes and goes. Persistent squinting, one eye kept closed, discharge, redness or pawing at the eye are signs of eye pain or infection and need a vet. Cats Protection also lists a hunched posture with squinted eyes among signs of pain. Read the whole cat, not just the eyes (see cat body language).
Slow blink FAQ
What does it mean when a cat slow blinks at you?
It is a relaxed, positive signal. Research published in Scientific Reports in 2020 suggests slow blinking works as positive emotional communication between cats and people.
Should I slow blink back at my cat?
Yes. In the 2020 study cats narrowed their eyes more when their owners slow blinked at them, and approached strangers more readily after a slow blink.
Is a slow blink a cat kiss?
That is a popular description, but the research shows only that slow blinking is linked to a relaxed state and makes cats more likely to approach, not that it has a specific meaning like affection.
Why is my cat squinting all the time?
Constant squinting, especially in one eye, or squinting with discharge or a hunched posture can mean pain or an eye problem. See a vet.
Sources
General education, not veterinary advice. If you are worried about your cat, contact your veterinarian; in an emergency, go to the nearest emergency vet.