👁️ See Like a Cat
Why does your cat walk straight past the bright red toy — and then spot a moth in a dim corner? Because their eyes are built differently from yours. Pick a scene or use your own photo, drag the divider, and see the world translated into cat vision: two-cone colour, muted saturation, softer sharpness, and low-light vision roughly six times more sensitive than ours.
Your scene & settings
Each scene demonstrates one fact: red fades, blue pops · green goes grey-yellow · cats own the dusk.
Drag & drop works too. Your photo is processed in your browser, on your device — it is never uploaded, stored, or sent anywhere.
Low-light basis: a cat's light sensitivity is thought to be about six times a human's (Cornell Feline Health Center) — more rods, plus the reflective tapetum lucidum. The lift amount here is a rendering choice; the six-times sensitivity is the sourced fact. Cats still cannot see in total darkness.
Wide field of view: an impression of ~200° vs our ~180° (edge stretch + softer edges). A flat photo can't gain real field of view — this only hints at it.
Near-focus blur: cats can't focus closer than ~30 cm, so the bottom of the frame — the whisker zone — softens.
The blur strength is a rendering approximation of that acuity range, not an exact optical conversion.
Cats have lower contrast sensitivity — research describes this qualitatively and publishes no percentage, so we keep it subtle and don't invent a number.
You vs your cat
What changed, and why
The download is one PNG: your view and the cat view side by side, with the approximation note printed on the card itself — no watermark across the photo.
The facts behind each slider
Every effect above traces to a row in this table — and every row was verified by reading the source in full. Where research gives no number (contrast), the tool invents none. Where a slider needs a rendering value (blur strength, low-light lift), the value is a visual approximation and is labelled as one — only the findings in this table are stated as facts.
| Parameter | What the research shows | Source (read in full) |
|---|---|---|
| Colour system | Cats are dichromats — two cone types, not three. "Cats are good at identifying yellows and blues. They're not very good at distinguishing red from green." Their baseline is comparable to red–green colour blindness in humans. | Rover — interview with Dr. Bruce Kornreich, Director of the Cornell Feline Health Center; CatLens colour guide |
| Cone peaks | Blue (S) cones peak at ~450 nm and green (M) cones at ~555 nm. There is no red (L) cone — the basis of the colour remap. | CatLens colour guide, from published feline cone research (Loop et al. 1987; Ringo et al. 1977) |
| Red, orange, pink | Red falls outside both cone sensitivities and reads as a dark greyish-brown; orange as a dull yellowish-brown; pink as a pale, washed-out grey. Purple reads as a shade of blue. | CatLens colour guide; Purina cat-vision explainer |
| Saturation | Colours are roughly 50% less saturated for cats than for us — hence the colour-muting slider's 50% default. | CatLens colour guide & world-vision guide |
| Sharpness (acuity) | About 20/100 to 20/200: what a human sees clearly at 100–200 feet, a cat needs to be at 20 feet to see as sharply. Cats are slightly nearsighted. | Purina cat-vision explainer; CatLens world-vision guide |
| Field of view | About 200° for cats vs about 180° for humans — wider peripheral vision for spotting movement at the edges. | Purina cat-vision explainer; Rover (Cornell interview) |
| Near focus | Cats can't focus on anything closer than ~30 cm (we manage ~10–15 cm). Their whiskers take over in that close zone — hence the near-focus blur toggle. | CatLens world-vision guide |
| Low-light sensitivity | Thanks to the tapetum lucidum, a cat's sensitivity to light "is thought to be about six times greater than that of a human's"; cats need roughly one-sixth of the light we do (Purina gives 5.5–7× better in dim light). They still cannot see in total darkness. | Cornell Feline Health Center, Cornell University College of Veterinary Medicine; Purina |
| Tapetum lucidum | A reflective layer behind the retina bounces light back through the photoreceptors for a second pass — and it's why cats' eyes glow in photos. | Cornell Feline Health Center |
| Contrast | Lower contrast sensitivity than humans — described qualitatively in the research, with no percentage published. Our slider is a subtle rendering choice, not a measurement. | CatLens colour guide |
| Ultraviolet | Cat lenses do transmit UV-A light that human lenses block — but an ordinary photo and screen contain no UV data, so UV is deliberately not simulated. Faking it would be inventing a picture, not translating one. | CatLens colour guide (2014 Proc. Royal Society B finding) |
Practical takeaway: blue and yellow toys and bowls are the easiest for a cat to spot. Red, orange and pink are poor choices — especially on a brown carpet or green lawn, where they fade into the background.
Why use this simulator?
Buy toys your cat can actually find
That premium red mouse isn't broken — on a brown carpet it's nearly invisible to your cat. Run a photo of your play area through the simulator before you shop, and you'll see why blue and yellow toys get pounced on and red ones get ignored.
Read your home through their eyes
The dim hallway corner you'd call "dark" is, to your cat, comfortably lit. The sharp-edged world you navigate is softer and wider for them. Seeing your rooms this way explains a lot of behaviour — the dusk zoomies included.
Your photo never leaves your device
No app install, no account, no upload. Every pixel is processed in your browser. Other simulators make you install an app or stay silent about where your photo goes — this one does the work locally and says so.
Questions people ask
Is this exactly what my cat sees?
No — and any tool that claims otherwise is overpromising. No tool can show another animal's subjective experience. This simulator translates the known physical differences in cat eyes — dichromatic (two-cone) colour vision peaking in blue (~450 nm) and green-yellow (~555 nm), roughly 50% lower colour saturation, visual acuity around 20/100–20/200, a wider ~200° field of view, and the ability to see in light about six times dimmer than humans need — into an image human eyes can interpret. Think of it as a translation, not a copy.
Can cats see in complete darkness?
No. Cats need about one-sixth of the light humans need — a moonlit or dim room is plenty — but in total darkness they can't see either. They navigate those moments with whiskers, hearing and memory.
Why does my cat ignore the red toy but chase the blue one?
Red sits outside both of a cat's cone sensitivities, so a red toy reads as a dark greyish-brown blob — on a brown carpet or green grass, it nearly disappears. Blue is the most vivid colour a cat sees, and yellow registers clearly too. Movement matters even more: a still toy of any colour is easy to miss, a moving one is not.
Why is there no UV mode?
Because it would be made up. Cat lenses do pass ultraviolet light, but your photo contains no UV information and your screen can't emit UV — so any "UV view" would be an artist's guess, not a simulation. We'd rather leave a gap than fake a feature.
Do my photos get uploaded or saved anywhere?
No. The photo is read locally by your browser and processed on a canvas on your device. Nothing is sent to a server, stored, or used for anything else. Refresh the page and it's gone.
My cat's eyes look cloudy, or they've started bumping into things — can this tool check their vision?
No — this tool simulates normal cat vision for curiosity only; it cannot test or assess an individual cat's eyes. If your cat's eyes look cloudy or different, or their behaviour changes — bumping into things, hesitating at stairs, missing jumps — don't try to diagnose it yourself. Book a veterinarian promptly; vision changes can have causes that need timely treatment.
Keep exploring
More ways to get inside your cat's world:
Cat Body Language Quiz — what those ears and tails are saying · What Breed Is My Cat? — identify likely breed traits · Can Cats Eat…? — food safety checker · All KittyButts tools
This simulator is an educational approximation of normal cat vision, built from the published findings listed above; render settings such as blur strength and low-light lift are visual approximations, not measurements. It is not medical advice and cannot assess your cat's eyesight. If your cat's eyes look cloudy or different, or their behaviour changes — bumping into things, hesitating at stairs, missing jumps — don't try to diagnose it yourself: book a veterinarian promptly; vision changes can have causes that need timely treatment.