Cat’s Eye.

I recently ran across the term “cat’s eye” and (since it clearly did not refer to a cat) was puzzled; looking it up, I discovered that “A cat’s eye or road stud is a retroreflective safety device used in road marking and was the first of a range of raised pavement markers.” The Wikipedia article has this history:

The inventor of cat’s eyes was Percy Shaw of Boothtown, Halifax, West Yorkshire, England. When the tram-lines were removed in the nearby suburb of Ambler Thorn, he realised that he had been using the polished steel rails to navigate at night. The name “cat’s eye” comes from Shaw’s inspiration for the device: the eyeshine reflecting from the eyes of a cat. In 1934, he patented his invention (patents Nos. 436,290 and 457,536), and on 15 March 1935, founded Reflecting Roadstuds Limited in Halifax to manufacture the items. The name Catseye is their trademark. […]

The blackouts of World War II (1939–1945) and the shuttered car headlights then in use demonstrated the value of Shaw’s invention and helped popularise their mass use in the UK. After the war, they received firm backing from a Ministry of Transport committee led by James Callaghan and Sir Arthur Young. Eventually, their use spread all over the world.

All over the world… except in the US: “The closest equivalent in the United States is the Stimsonite retroreflective raised pavement marker. Stimsonite markers are made out of plastic, not metal, and were first invented in 1963.” I guess this is one of those transatlantic differences, but one I’d never learned about. Are any of my US readers familiar with the term, and am I correct in thinking it’s well known to those in the UK?


  1. Yes, very familiar to me, and I can attest to their effectiveness, whether on unlit country roads at night or as lane markers on well-lit highways. One of their ingenious aspects is that when wheels drive over them, the rubberized mounting is compressed and cleans dirt and crud from the surface of the reflectors, like blinking.

    It’s always puzzled me that they have not been adopted in the US. They are a cheap addition to the cost of building roads and very helpful to drivers. Maybe just a case of ‘not invented here’ syndrome.

  2. In these parts they are called Bott’s dots.

  3. I knew that cat’s eye was the term the British used for retroreflective road markers, but I was unaware of how they differed from the American versions—which are shaped like pyramidal frusta and (as noted) made out of plastic. From their name, I would probably have guess that the cat’s eyes were round, like the Bott’s dots* Y mentions, except reflective (which the dots normally are not).

    * The linked WIkipedia article says they are called “turtles” in the Pacific Northwest, but I think we just called them “road dots” when I was a kid.

  4. David Marjanović says

    Not used in mainland Europe. Instead, the paint of the lines on roads contains tiny glass beads and is therefore reflective.

  5. Bathrobe says

    iIRR, when I played marbles as a kid, the cat’s eye was the name of the large marble. (There were many small marbles but only a few (maybe only one?) large ones.)

  6. Well do I remember the merry call-and-response of the rare latenight childhood cartrips in Darkest West Cork:

    children: “… eye, eye, eye, eye …”

    parents: “that’s enough now”

    children: “… eye, eye, eye, eye …”

    parents: “that’s enough now”

  7. Lars Mathiesen says

    Reflective signage is used here, including on license plates — the kind with little lenses on sheet metal, but I’ve never seen the UK-style road dots here. Maybe because when they are needed the most, they will be covered by snow. (Driving in the UK, it could almost be too much because each row of dots seemed to have a different color. I suppose it’s easier if you trained in that system).

    EDIT: I tell a lie, I’ve actually seen them used on the midline of a bidirectional bike path through a forest. I was there in daylight so I don’t know how well they served their purpose.

    FWIW, katteøje in Danish is a little round reflector on the rear mudguard of bikes, using lots of little corner reflectors molded in the back surface of the red translucent plastic — possibly metal plated for better reflectivity).

  8. (ex) Brit here. Yes very familiar with Cat’s Eyes. And the story of Percy Shaw — I seem to remember a BBC doco about him, in which he spoke with a Halifax accent.

    I’m now in New Zealand, and yes we have the reflective white lines; and/or plastic ‘turtles’ (good name!).

    I guess that installing Cat’s Eyes might make the roadbuilding more expensive? You have to sink their metal base into the tar-seal, to give the rubbery bit something to retract into.

  9. @David Marjanović: Line paint in America sometimes has those reflective beads, but it’s not the norm. You are only likely to see the extra shiny lane lines on major arteries. (A few months ago, a small truckload of white line paint fell off a truck in front of me as I was driving and spilled all over the road. I was only two cars behind, and it was a fast, heavily-trafficked, two-land road, so I had neither the time nor space to avoid the paint puddle entirely, although I did the best I could. I ended up with the paint spattered all over the lower part of my vehicle, and although I cleaned it off the sides, there is a lot still present on the undercarriage. As a result of this encounter, I have become quite familiar with the properties of the paint that is used for lane lines on minor thoroughfares.)

    @Bathrobe: Cat’s eye is a style of marbles, not a size. The style is mostly transparent glass, but with more colorful inclusions strung out between antipodal points on the surface, vaguely like a feline pupil. In my lifetime, it seems like most of the marbles I played with and my kids have played with were cat’s eyes, while my uncle’s older marble collection was much more heterogeneous.

    Large marbles are most commonly “shooters,” because of the role they play in the game of marbles, stricto sensu. The shooters (also known as “bigs,” “bosses,” “taws,”* and various compound names—“big shooters” was what I usually called them) are the ones fired into the circle to knock the other players’ marbles around.

    * I had no idea where taw came from, and apparently nobody else knows either. The OED says: “Origin unascertained, and order of senses uncertain: perhaps, like alley,… an abbreviation.” The relevant sense of alley** is:

    A toy marble… originally one of high quality made from marble or alabaster, later also one made from glass or other material. Also (occasionally) attributive in alley taw.

    While this provides a transparent etymology, by shortening, for alley, I have no idea was taw could have been short for. The OED has three senses of taw n.3:

    1. A large choice or fancy marble, often streaked or variegated, being that with which the player shoots.
    2. transferred. A game played with such marbles.
    3. The line from which the players shoot in playing the game.

    The first two sense are both attested in early (1709) editions of Tatler, so the “transferred” is (as noted under the etymology) apparently a best guess, and it might have actually gone the other way. Wiktionary does no better on the etymology, but it does present some further evolved senses:

    3. (square dancing) A dance partner.
    Walk around your corner; see-saw around your taw.
    4. A favorite person; beloved, partner, spouse.

    The development is apparently preferred marble > preferred partner.

    ** The OED also includes one interesting phrase with alley:

    to toss (pass, throw, etc.) in one’s alley Australian slang: to give up, finish; to die; = to pass in one’s marble… Now rare.

  10. катафот
    Borrowed from Ancient Greek κατά (katá, “downwards”) + φωτός (phōtós, “light”).
    IPA(key): [kətɐˈfot]
    катафо́т • (katafót) m inan (genitive катафо́та, nominative plural катафо́ты, genitive plural катафо́тов)

    1. retroreflector, cat’s eye


  11. Athel Cornish-Bowden says

    Universally known and understood under that name in the UK, but I think that

    Eventually, their use spread all over the world

    is wishful thinking. I’ve never come across them anywhere else.

  12. Ben Tolley says

    @ Brett

    While the whole thing isn’t round, the reflectors are, and arranged in pairs, so they are rather eye-like – it’s not obvious in daylight, but they’re the two little circles on the front on the first photo on Wikipedia.

    And yes, they’re well known to me in the UK, and probably to everyone, whether they drive or not. I certainly knew what they were from a fairly young age and found them fascinating as a child.

  13. I have seen them in Canada. However, my understanding is that they are not used more widely here because trials have shown that they tend to take too much of a beating from snow plows.

  14. Kate Bunting says

    An old aunt of my father’s was convinced that they were electric lights that an approaching car somehow caused to be switched on!
    I had no idea they were unique to the UK. I have never driven in Europe, but I have travelled by road in various countries and never noticed the absence of cats’ eyes.

  15. FWIW, katteøje in Danish is a little round reflector on the rear mudguard of bikes, using lots of little corner reflectors molded in the back surface of the red translucent plastic — possibly metal plated for better reflectivity)
    That’s also the meaning of Katzenauge that I am familiar with. Until I saw the link to the German Wikipedia Hat posted, I didn’t even know that reflectors used on roads are called the same way. And, in support of DM, one doesn’t often find reflectors on German roads at ground level; normally they are on the Leitpfosten (“reflector posts”, duh).

  16. Lars Mathiesen says

    Once driving in the UK, we kids managed to fool my Mom into thinking that the cars with white license plates were only allowed to drive in one direction, and those with yellow in the other. In her excuse, Danish cars have two white license plates if registered for private use, and two yellow ones if commercial.

  17. Jen in Edinburgh says

    I’ve never seen cats’ eyes on a cycle path, but they do sometimes have flat solar powered lights (i.e. charge during the day and shine at night)

  18. Lars Mathiesen says

    solar powered lights — that may well have been what I saw, I just assumed they were reflectors.

  19. I came across the term in one of the first seasons of the British “game show” QI, where all participants used it with no explanation; it took me a while to figure out with the help of the Hebrew calque einei xatul, which I’d known but didn’t hear very often and had thought was a local (even familial) nickname.

  20. Cat’s eye is not unknown in Australia, but is not commonly used. Reflective marking is the term i’ve usually heard.

    Cat’s eye is the name used in Croatia though.

  21. A suspicion had been slowly growing in my mind, as the decades went by, that “cat’s-eye” must have some referent other than “those clear marbles with twists of color inside,” so this post & its comments have taken a weight off. Thanks!

  22. Jen in Edinburgh says

    that may well have been what I saw, I just assumed they were reflectors

    I don’t know what Danish cyclepaths have, I just admire the cleverness of those little marker lights 🙂

    I feel like seeing actual cat’s eyes reflecting must have been a more common thing to the people who first named them than it is now – maybe you see the effect more often using a torch rather than relying on streetlights etc?

  23. Lars Mathiesen says

    You don’t see cats’ eyes reflect under streetlights — they have a reflective layer under the retina so photons get two chances to impact the cones and rods, but that also means that they reflect back in a very narrow angle to where the light is coming from. Same principle as that reflective sheet metal, really, your light source makes a point image (ideally) on the retina so the reflection becomes a beam with infinite focal length (ideally again) pointed back at the light source. But with enough not-so-ideal deviation that if you are holding a torch, you see it.

    So going around a bend on a dark road is when you may see your headlights reflected from a cat’s eyes, because the light points into the forest or field — or a deer’s, I think those are the ones I see most often.

    The corner reflectors of a road dot or a bike safety reflector are something completely different, no lenses involved. In that sense, the cat’s eye/katteøje designations are fallacious.

  24. I bethought me of a Mad Magazine classic.

  25. Ah, 1¢ postage — those were the days!

  26. Owlmirror says

    I have a faint memory of reading an older version of “Pippi Longstocking”, which had a line about Mr. Nilsson (the monkey) doing something like “making cat’s eyes with a mirror”, which, after some thought, I understood as meaning “reflecting light from the mirror onto various surfaces”. However, later editions of the same book changed the wording, and the current text reads (more vaguely, I think), “playing with a mirror”.

    As I think about it more, I think the text was actually longer, and had something about the monkey managing to reflect the light into Tommy’s [one of Pippi’s friends] eye.

    Does anyone recognize the idiom of “making cat’s eyes”?

    And if anyone has an older edition or non-English edition of the book, does it in fact say anything like what I wrote?

  27. January First-of-May says

    I bethought me of a Mad Magazine classic.

    The experiment of putting advertisements on postage stamps had in fact been done in New Zealand in 1893.
    Unfortunately, they decided to place the ads on the back side of the stamps, with the result that the ads were only seen by the original purchasers and the stamp collectors; with the stamp affixed to the letter (as usually intended), the ad was hidden.
    As such, the experiment was a complete failure, and ended after only a few months.

    [Those stamps are now somewhat collectible, though (somewhat unexpectedly) not especially rare as stamps go. I got mine for less than a dollar.]

  28. I’ve known the term for decades, but as a type of optical component, used to reflect light back to its source without changing the polarization (unlike the much more commonly-used corner-cube)–nothing to do with road marking. I’d thought that the road versions here (California) were Bott’s dots, but Wikipedia informs me that those are nonreflective bumps.

    Learn something new every day.

  29. Lars Mathiesen says

    @DCA, this one? The cat’s-eye retroreflector is a passive optical system consisting of a secondary mirror placed at the focal point of a primary lens. That’s how an animal eye does it too.

  30. they are commonly installed in S. Africa too, very helpful when I was learning to drive in Cape Town and the sea fogs came rolling in..
    As JJM says, my understanding is they aren’t much used in the US as the snow ploughs tend to rip them out..

  31. My experience may be unusual b/c I lived near Texas Transportation Institute for probably its whole existence (until I moved a few months ago), but I’m in the habit of driving on roads that have both reflective stripes and raised reflective markers–typically a stripe, a space, a marker, another space, another stripe, rinse, repeat…The raised markers are especially helpful for driving in rain, where they normally peek out above the water on the road, or driving on them causes a “bump” that lets drivers know they’re veering out of the lane. This seems to be the pattern for most major roads throughout Texas; secondary roads usually also have at least reflective stripes, and near TTI, at least, they may also have markers or other “experimental” devices.

    I haven’t paid enough attention in California to know where/if the markers are used here; I’m still too busy trying to find my way around!

  32. I recognize cat eyes/ cat’s eye as a term for some sort of reflective marking, but I’m not familiar with the particular style of road bumps that’s on the linked pages. Rumble strips I know about, but that’s not the same thing.

    The game with the mirror (or a watch) is well known of course, but I don’t remember that scene in the book. Perhaps because I was more fond of the movies?

  33. Owlmirror says

    [As usual, I probably overdid the research. Oh, well.]

    It looks like I misremembered more than I thought.

    The book seems to have been the second in the series, not the first. I found that there seem to be at least 3 or 4 English translations. And the phrase seems to have been “sun cat”, not “cat’s eye”. I don’t think that the phrase derives from the Swedish “solplet”, so maybe some dialect phrase?

    I thought that the difference in translations was older vs. newer, but the phrase can be heard in a reading from the 2020 Youtube link, and the book she’s reading looks like a modern printing, but I found the alternate phrasing without “sun cat” in a book from 1985. I am pretty sure I read both variants in books from before 1985. The translations seem to both be by Florence Lamborn. While they might vary in other places as well, the rest of the wording for the specific paragraph looks the same.

    I have additional translations besides these, but I think this is enough for a comment posting, for now. None of the other translations use a term that looks like it might be a calque or variant of “sun cat”.

    Pippi Langstrømpe går om bord / Pippi Goes On Board / Pippi Goes Aboard / Pippi Longstocking Goes Aboard
    Pippi er med på skoleudflugt / Pippi Goes to the School Picnic / Pippi Goes on a School Outing


    Der lød trampen af mange fødder på vejen og masser af snak og latter. Der kom Tommy med sin rygsæk på ryggen og Annika i en splinterny bomuldskjole og deres frøken og alle deres klassekammerater, undtagen en stakkel, som havde fået ondt i halsen lige akkurat den dag, hvor de skulle på udflugt. Og dér, foran alle de andre, red Pippi på sin hest. Bag hende sad hr. Nilsson med sit lommespejl i hånden. Han sad og lavede solpletter med det og så så inderligt fornøjet ud, når det lykkedes ham at placere en solplet lige i øjet på Tommy.

    English 1:

    There was a tramping of many feet on the ground, and much talk and laughter. There was Tommy with a knapsack on his back, and Annika in a brand-new cotton dress, and their teacher and all their classmates except one poor child who had the misfortune to get a sore throat on the very day of the picnic. And there in front of all the others was Pippi, riding on her horse. Back of her sat Mr. Nilsson with his pocket mirror in his hand. Yes, there he sat, making “sun cats” with the mirror and looking extraordinarily pleased when he managed to put a sun cat right in Tommy’s eye.

    English 2:

    There was a tramping of many feet on the ground, and much talk and laughter. There was Tommy with a knapsack on his back, and Annika in a brand-new cotton dress, and their teacher and all their classmates except one poor child who had the misfortune to get a sore throat on the very day of the picnic. And Pippi, riding there in front of all the others on her horse. Back of her was sat Mr. Nilsson with his pocket mirror in his hand. Yes, there he sat, catching the sun’s light in the mirror and looking extraordinarily pleased when he managed to reflect it right in Tommy’s eye.

  34. As usual, I probably overdid the research.

    I don’t understand the concept.

  35. January First-of-May says

    Oooh! I know what it is: they’re talking about what in Russian is called солнечные зайчики (literally “sun hares”).

    I’m not aware (at least offhand) of any term for this in English; perhaps the game itself is not known. IIRC my mother actually asked about the English term for them on Facebook a few years ago, and didn’t get an answer.

  36. Owlmirror says

    A lucky hit in Google Books:

    Strindberg and Genre, by Michael Robinson. 1991

    Only snippet view is available, so the citation is choppy:

    oss det solsken som dess morgon lovade’ (The evening of life has finally given us the sunshine its morning promised — p. 15). Basking in this metaphorical sunlight, the old couple can almost forgive their envious neighbors and their ungrateful children. The dancing sunbeam (en solkatt, literally a ‘sun-cat’) that suddenly shimmers on the wall of the mausoleum seems to the Wife to be a good omen: ‘Det
    can brighten it; and the orphan he has plundered and pushed into the life of a chimney sweep seems permanently besmirched. But whereas the imagery of darkness in this play is quite conventional, the light imagery is strikingly original. The Wife first sees the dancing sunbeam (‘sun-cat’) just after she speaks of dissolving Amalia’s marriage ; its subsequent appearances always highlight their evil deeds

    August Strindberg was indeed a Swedish playwright, and searching for “en solkatt” finds many hits — in Swedish.

    Including in a song by ABBA!

    The translator above gives “gleam” for “solkatt”, but “sunbeam” seems obviously more correct.

    The actual English version of the song doesn’t reference suncats/sunbeams at all.

    Google translate only offers the literal translation for “solkatt”. Oh, wait. I see that if I click on the translated term “sun cat”, another option does pop up: “reflection of the sun/reflektion av solen”.

    So it looks like it’s a known Swedish idiom. And for some reason, the translator (of one version of “Pippi Goes on Board”) decided to use a calque of it in the English translation, even though “solkatt” doesn’t seem to have been used in the original, and the term is unknown in English.

    Hm. I wonder if a different edition of the Swedish originally used “solkatt(er)” and for some reason later changed it to “solplet(ter)”? Or maybe the other way around?

  37. Yes, I recently tried to read K.S. Robinson in English. I did not like it, but I noted that it is the first time I come across something similar to солнечный зайчик in English. Having this said:

    – I do not remember every reading words солнечный зайчик in Russian
    – I do not read fiction often and when I did I did not know English.

    The line was
    Behind her, down the avenue to the west, mirrorflakes of broken sunlight bounced
    on the big river.
    ” K.S.R., 2312

    The phenomenon that he describes is different of course. Not spots on a matte surface, but reflections. But “mirrorflakes” made me wonder if it is flakes created by a mirror of flakes of mirror.

  38. Google offers on its first page: “The surface of the lake winkles in a mirrorflake curl, approaching them fast, and when the gust causing the cat’s paw hits them, the boat heels hard.“, K.S.R. Aurora
    Night beach and big-handed children, running the mirrorflake road on the sea…” , K.S.R., A Short Sharp Shock

    To which Google Books add: “Coarse – grained sand sparked with reflected moonlight , and the fish arched to the shape of the crescent moon , which hung over the horizon at the end of a mirrorflake path of water . “, K.S.R., A Short Sharp Shock
    Looking toward the sun, off to his left, made it like noon, and the snow blazed in a mirrorflake fan., K.S.R. Antarctica
    As for me: the moon lays a mirrorflake road to the horizon. “, K.S.R. The Wild Shore.

    I read Aurora but did not notice.

  39. Trond Engen says

    Owlmirror: Hm. I wonder if a different edition of the Swedish originally used “solkatt(er)” and for some reason later changed it to “solplet(ter)”? Or maybe the other way around?

    Neither. Pippi er med på skoleudflugt is Danish, and solplet(ter) is how the Danish translator chose to render it.

  40. Owlmirror says

    @Trond: Thank you for correcting my continued mistake. I was so pleased to find a text that could be previewed I forgot to double-check the exact Scandinavian language it used. How embarrassing.


    With that in mind, and now that I know where I goofed up, I see that Google Books does have “Pippi Långstrump går ombord”, the actual Swedish original, but only with snippet view.

    I am able to see, though, that the original text does indeed have “solkatt”:


    Och där framför alla de andra red Pippi på sin häst. Bakom henne satt Herr Nilsson med sin fickspegel i handen. Han satt ock gjorde solkatter med den och såg så innerligt förnöjd ut, när han lyckades placera en solkatt mitt i ögat på Tommy.

    So even though the term is not used in other Scandinavian languages, the translator did indeed use a calque for an English translation, but then changed it.

  41. John Cowan says

    When I was a child and in bed sick, I played a game with flashing the sunlight around the room with a mirror. I think my mother taught me this, and she gave me a name for it that I can’t remember; I thought it was sun dog, but that’s a meteorological effect. She was a native germanophone with excellent English (except for her phonology), for what that’s worth.

  42. John Cowan, солнечный зайчик is that exact thing.

    Hares are our bunnies: cute little things with ears and the classic prey (in fairy tales). Except one thing: 30-50 mph in short distances and really long legs.

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