Nail

Nail (pronounced neyl)

(1) A slender, typically rod-shaped rigid piece of metal, usually in many lengths and thicknesses, having (usually) one end pointed and the other (usually) enlarged or flattened, and used for hammering into or through wood, concrete or other materials; in the building trades the most common use is to fasten or join together separate pieces (of timber etc).

(2) In anatomy, a thin, horny plate, consisting of modified epidermis, growing on the upper side of the end of a finger or toe; the toughened protective protein-keratin (known as alpha-keratin, also found in hair) at the end of an animal digit, such as fingernail.

(3) In zoology, the basal thickened portion of the anterior wings of certain hemiptera; the basal thickened portion of the anterior wings of certain hemiptera; the terminal horny plate on the beak of ducks, and other allied birds; the claw of a mammal, bird, or reptile.

(4) Historically, in England, a round pedestal on which merchants once carried out their business.

(5) A measure for a length for cloth, equal to 2¼ inches (57 mm) or 1⁄20 of an ell; 1⁄16 of a yard (archaic); it’s assumed the origin lies in the use to mark that length on the end of a yardstick.

(6) To fasten with a nail or nails; to hemmer in a nail.

(7) To enclose or confine (something) by nailing (often followed by up or down).

(8) To make fast or keep firmly in one place or position (also used figuratively).

(8) Perfectly to accomplish something (usually as “nailed it”).

(9) In vulgar slang, of a male, to engage in sexual intercourse with (as “I nailed her” or (according to Urban Dictionary: “I nailed the bitch”).

(10) In law enforcement, to catch a suspect or find them in possession of contraband or engaged in some unlawful conduct (usually as “nailed them”).

(11) In Christianity, as “the nails”, the relics used in the crucifixion, nailing Christ to the cross at Golgotha.

(12) As a the nail (unit), an archaic multiplier equal to one sixteenth of a base unit

(13) In drug slang, a hypodermic needle, used for injecting drugs.

(14) To detect and expose (a lie, scandal, etc)

(15) In slang, to hit someone.

(16) In slang, intently to focus on someone or something.

(17) To stud with or as if with nails.

Pre 900: From the Middle English noun nail & nayl, from the Old English nægl and cognate with the Old Frisian neil, the Old Saxon & Old High German nagal, the Dutch nagel, the German Nagel, the Old Norse nagl (fingernail), all of which were from the unattested Germanic naglaz.  As a derivative, it was akin to the Lithuanian nãgas & nagà (hoof), the Old Prussian nage (foot), the Old Church Slavonic noga (leg, foot), (the Serbo-Croatian nòga, the Czech noha, the Polish noga and the Russian nogá, all of which were probably originally a jocular reference to the foot as “a hoof”), the Old Church Slavonic nogŭtĭ, the Tocharian A maku & Tocharian B mekwa (fingernail, claw), all from the unattested North European Indo-European ənogwh-.  It was further akin to the Old Irish ingen, the Welsh ewin and the Breton ivin, from the unattested Celtic gwhīnā, the Latin unguis (fingernail, claw), from the unattested Italo-Celtic əngwhi-;the Greek ónyx (stem onych-), the Sanskrit ághri- (foot), from the unattested ághli-; the Armenian ełungn from the unattested onogwh-;the Middle English verbs naile, nail & nayle, the Old English næglian and cognate with the Old Saxon neglian, the Old High German negilen, the Old Norse negla, from the unattested Germanic nagl-janan (the Gothic was ganagljan).  The ultimate source was the primitive Indo-European h₃nog- (nail) and the use to describe the metal fastener was from the Middle English naylen, from the Old English næġlan & nægl (fingernail (handnægl)) & negel (tapering metal pin), from the Proto-Germanic naglaz (source also of Old Norse nagl (fingernail) & nagli (metal nail).  Nail is a noun & verb, nailernailless & naillike are adjectives, renail is a verbs, nailing is a noun & vern and nailed is a verb & adjective; the noun plural is nails.

Nail is modified or used as a modifier in literally dozens of examples including finger-nail, toe-nail, nail-brush, nail-file, rusty-nail, garden-nail, nail-fungus, nail-gun & frost-nail.  In idiomatic use, a “nail in one's coffin” is a experience or event that tends to shorten life or hasten the end of something (applied retrospectively (ie post-mortem) it’s usually in the form “final nail in the coffin”.  To be “hard as nails” is either to be “in a robust physical state” or “lacking in human feelings or without sentiment”. To “nail one's colors to the mast” is to declare one’s position on something.  Something described as “better than a poke in the eye with a rusty nail” is a thing, which while not ideal, is not wholly undesirable or without charm.  In financial matters (of payments), to be “on the nail” is to “pay at once”, often in the form “pay on the nail”.  To “nail something down” is to finalize it. To have “nailed it” is “to perfectly have accomplished something” while “nailed her” indicates “having enjoyed sexual intercourse with her”.  The “right” in the phrase “hit the nail right on the head” is a more recent addition, all known instances of use prior to 1700 being “hit the nail on the head” and the elegant original is much preferred.  It’s used to mean “correctly identify something or exactly to arrive at the correct answer”.  Interestingly, the Oxford English Dictionary (OED) notes there is no documentary evidence that the phrase comes from “nail” in the sense of the ting hit by a hammer.

Double-headed nails.

Double-headed nails are used for temporary structures like fencing.  When the shaft is hammered in to the point where the surface of the lower head is flat against the surface of that into which it's being hammered, it leaves the upper head standing proud with just enough of the shaft exposed to allow a claw-hammer to be used to extract nail.  There is a story that as part of an environmental protest against the building or demolition of some structure (the tales vary), activists early one morning went to the temporary fencing around the contested site and hammered in all the double-headed nails.  This is believed to be an urban myth.

The sense of “fingernail” appears to be the original which makes sense give there were fingernails before there were spikes (of metal or any other material) used to build stuff.  The verb nail was from the Old English næglian (to fix or fasten (something) onto (something else) with nails), from the Proto-Germanic ganaglijan (the source also of the Old Saxon neglian, the Old Norse negla, the Old High German negilen, the German nageln and the Gothic ganagljan (to nail), all developed from the root of the nouns.  The colloquial meaning “secure, succeed in catching or getting hold of (someone or something)” was in use by at least the 1760; hence (hence the law enforcement slang meaning “to effect an arrest”, noted since the 1930s.  The meaning “to succeed in hitting” dates from 1886 while the phrase “to nail down” (to fix in place with nails) was first recorded in the 1660s.

Colors: Lindsay Lohan with nails unadorned and painted.

As a noun, “nail-biter” (worrisome or suspenseful event), perhaps surprisingly, seems not to have been in common use until 1999 an it’s applied to things from life-threatening situations to watching close sporting contests.  The idea of nail-biting as a sign of anxiety has been in various forms of literature since the 1570s, the noun nail-biting noted since 1805 and as a noun it was since the mid-nineteenth century applied to those individuals who “habitually or compulsively bit their fingernails” although this seems to have been purely literal rather than something figurative of a mental state.  Now, a “nail-biter” is one who is “habitually worried or apprehensive” and they’re often said to be “chewing the ends of their fingernails” and in political use, a “nail biter” is a criticism somewhat less cutting than “bed-wetter”.  The condition of compulsive nail-biting is the noun onychophagia, the construct being onycho- (a creation of the international scientific vocabulary), reflecting a New Latin combining form, from the Ancient Greek ὄνυξ (ónux) (claw, nail, hoof, talon) +‎ -phagia (eating, biting or swallowing), from the Ancient Greek -φαγία (-phagía).  A related form was -φαγος (-phagos) (eater), the suffix corresponding to φαγεῖν (phageîn) (to eat), the infinitive of ἔφαγον (éphagon) (I eat), which serves as aorist (essentially a compensator for sense-shifts) (for the defective verb ἐσθίω (esthíō) (I eat).  Bitter-tasting nail-polish is available for those who wish to cure themselves.  Nail-polish as a product dates from the 1880s and was originally literally a clear substance designed to give the finger or toe-nails a varnish like finish upon being buffed.  By 1884, it was being sold as “liquid nail varnish” including shads of black, pink and red although surviving depictions in art suggests men and women in various cultures have for thousands of years been coloring their nails.  Nail-files (small, flat, single-cut file for trimming the fingernails) seem first to have been sold in 1819 and nail-clippers (hand-tool used to trim the fingernails and toenails) in 1890.

Francis (1936-2025; pope 2013-2025) at the funeral of Cardinal George Pell (1941-2023), St Peter’s Basilica, the Vatican, January 2023.

The expression "nail down the lid" is a reference to the lid of a coffin (casket), the implication being one wants to make doubly certain anyone within can't possible "return from the dead".  The noun doornail (also door-nail) (large-headed nail used for studding batten doors for strength or ornament) emerged in the late fourteenth century and was often used of many large, thick nails with a large head, not necessarily those used only in doors.  The figurative expression “dead as a doornail” seems to be as old as the piece of hardware and use soon extended to “dumb as a doornail” and “deaf as a doornail).  The noun hangnail (also hang-nail) is a awful as it sounds and describes a “sore strip of partially detached flesh at the side of a nail of the finger or toe” and appears in seventeenth century texts although few etymologists appear to doubt it’s considerably older and probably a folk etymology and sense alteration of the Middle English agnail & angnail (corn on the foot), from the Old English agnail & angnail.  The origin is likely to have been literally the “painful spike” in the flesh when suffering the condition.  The first element was the Proto-Germanic ang- (compressed, hard, painful), from the primitive Indo-European root angh- (tight, painfully constricted, painful); the second the Old English nægl (spike), one of the influences on “nail”.  The noun hobnail was a “short, thick nail with a large head” which dates from the 1590s, the first element probably identical with hob (rounded peg or pin used as a mark or target in games (noted since the 1580s)) of unknown origin.  Because hobnails were hammered into the leather soles of heavy boots and shoes, “hobnail” came in the seventeenth century to be used of “a rustic person” though it was though less offensive than forms like “yokel”.

Nails and pins

Mug shot “pin” from TeePublic featuring Lindsay Lohan (b 1986, left), Donald Trump (b 1946; POTUS 2017-2021 and since 2025) and Paris Hilton (b 1981, right).  In this context, although the product really is “the badge”, the name was gained from the built-in pin supplied to secure the object to clothing.

As designs, a nail and a pin are similar, obviously differing only in scale but the function of each is different.  A nail’s primary purpose is to function as a structural fastener joining materials (most typically two or more pieces of wood) although there are specialized nails driven into substrate by impact (variously with hammers or nail guns (sometimes called “pin-nailers”, some of which are built to fire “panel pins” (very slender nails) or small “headless nails”).  A nail relies on friction and compression in the surrounding material for its holding strength.  Pins look like scaled-down nails but mostly are used for alignment, retention or pivoting, rather than structural load-bearing.  Because of their more delicate construction, pins often are inserted through specific-purpose, pre-existing holes and in many cases are intended to be temporary and are thus removable.  Visually, both nails and pins have heads (round, flat, clipped etc) and a tapered shank with a tip pointed for pointed tip for penetration (“snub-nosed” nails do exist but are rare) and both are designed slightly to deform the surrounding material when driven.  The most obvious difference is that a pin’s head is very small and some are spherical and made from plastic; they’re designed only to be pushed with finger-pressure rather than being hit with a hammer.  Although the term “pin” is used for some specialized devices used in building and engineering (dowel pin, pivot pin, gudgeon pin (also as wrist pin), roll pin, cotter pin etc), the word is most associated with the tailor’s pin (used mostly in textiles and usually clipped to “pin”).  In jewelry design and textiles there are also variants including the “lapel pin” and the fashion industry’s device of last resort, the “safety pin”.

Pinhead in publicity shot for Hellraiser III: Hell on Earth (1992).

Clive Barker's (b 1952) supernatural horror movie Hellraiser (1987) was based on his novella The Hellbound Heart (1986) and was a surprise hit, making it a franchise which has thus far spawned nine sequels, the most recent released in 2022.  The plot involved a mysterious puzzle box that, when opened, summoned the Cenobites, a group of extra-dimensional, sadomasochistic beings unable to differentiate between pain and pleasure.  It was a good premise for a horror movie but the character who really captured the audience's imagination was the unnamed figure viewers dubbed “Pinhead”.  Although Pinhead appeared in the original film for fewer than ten minutes, the character became the franchise’s focal point and has since dominated the publicity material for subsequent releases.  The popularity of Hellraiser has been maintained and it’s hoped that for the next release the producers will offer the part to Peter Dutton (b 1970; leader of the Liberal Party of Australia 2022-2025).

Peter Dutton captured by a photographer during a happy moment (left), Pinhead with the box able to summon the Cenobites (centre) and and artist's depiction of Mr Dutton in “Pinhead mode” (digitally altered image, right).

No longer burdened with tiresome parliamentary duties since losing his seat in the 2025 Australian general election, Mr Dutton has time for a third career and he should be good at playing an unsmiling character who speaks in a relentless monotone; really, all he need do is act naturally.  It’s suspected also he’ll be good at learning a script given the decades he spent parroting “talking points” and TWS (three word slogans).  While it’s an urban myth Mr Dutton wasn’t offered the part of Lord Voldemort in the Harry Potter movie franchise because he was deemed “too scary”, as Pinhead he’d be “just scary enough”.  While the LNP (Liberal National Party) state government in Queensland recently has appointed Mr Dutton to the board of the QIC (Queensland Investment Corporation, the investment manager of the state’s Aus$135 billion in assets), it’s understood his duties in the Aus$130,000 per annum role will be neither onerous or time-consuming so there’ll be ample opportunity for film-shoots.  Although when in opposition the LNP had decried the ALP (Australian Labor Party) government’s frequent appointment of ALP figures to lucrative sinecures, once in office the LNP continued the “jobs for the boys” tradition.  In the modern era, the two most striking characteristics of right-wing fanatics is (1) a fondness for sitting safely in a bunker while advocating for (and sometimes sending) other people's children to go a fight a war somewhere and (2) after a career spent extolling the virtues of “private enterprise” and criticizing “government waste”, being anxious to get back on the public payroll as soon as their political careers end.  Reassuringly for taxpayers who may have been worried Mr Dutton would not be able to continue to enjoy the lifestyle to which their taxes made him accustomed (“entitled” as he might have put it), it’s believed his director’s fees from QIC will not affect his parliamentary pension (understood to be between Aus$260,000-Aus$280,000 per annum).

The Buick Nailhead

In the 1930s, the straight-8 became a favorite for manufacturers of luxury cars, attracted by its ease of manufacture (components and assembly-line tooling able to be shared with those used to produce a straight-6), the mechanical smoothness inherent in the layout and the ease of maintenance afforded by the long, narrow configuration, ancillary components readily accessible.  However, the limitations were the relatively slow engine speeds imposed by the need to restrict the “crankshaft flex” and the height of the units, a product of the long strokes used to gain the required displacement.  By the 1950s, it was clear the future lay in big-bore, overhead valve V8s although the Mercedes-Benz engineers, unable to forget the glory days of the 1930s when the straight-eight W125s built for the Grand Prix circuits generated power and speed Formula One wouldn’t see until the 1980s, noted the relatively small 2.5 litre (153 cubic inch) displacement limit for 1954 and conjured up a final fling for the layout.  Used in both Formula One as the W196R and in sports car racing as the W196S (better remembered as the 300 SLR) the new 2.5 & 3.0 litre (183 cubic inch) straight-8s, unlike their pre-war predecessors, solved the issue of crankshaft flex (the W196's redline was 9500 compared with the W125's 5800) by locating the power take-off at the centre, adding mechanical fuel-injection and a desmodromic valve train to make the things an exotic cocktail of ancient & modern (on smooth racetracks and in the hands of skilled drivers, the swing axles at the back not the liability they might sound).  Dominant during 1954-1955 in both Formula One & the World Sports Car Championship, they were the last of the straight-8s in top-line competition.

Schematic of Buick “Nailhead” V8, 1953-1966.

Across the Atlantic, the US manufacturers also abandoned their straight-8s.  Buick introduced their overhead valve (OHV) V8 in 1953 but, being much wider than before, the new engine had to be slimmed somewhere to fit between the existing inner-fenders (it would not be until later the platform was widened).  To achieve this, the engineers narrowed the cylinder heads, compelling both a conical (the so-called “pent-roof”) combustion chamber and an arrangement in which the sixteen valves pointed directly upwards on the intake side, something which not only demanded an unusual pushrod & rocker mechanism but also limited the size of the valves.  So, the valves had to be tall and narrow and, with some resemblance to nails, they picked up the nickname “nail valves”, morphing eventually to “nailhead” as a description of the whole engine.  The valve placement and angle certainly benefited the intake side but the geometry compromised the flow of exhaust gases which were compelled by their anyway small ports to make a turn of almost 180^o on their way to the tailpipe.  As an indication of the heat-soak generated by that 180^o turn, the surrounding water passages were very wide. 

It wasn't the last time the head design of a Detroit V8 would be dictated by considerations of width.  When Chrysler in 1964 introduced the 273 cubic inch (4.5 litre) V8 as the first of its LA-Series (that would begat the later 318 (5.2), 340 (5.5) & 360 (5.9) as well as the V10 made famous in the Dodge Viper), the most obvious visual difference from the earlier A-Series V8s was the noticeably smaller cylinder heads.  The A engines used as skew-type valve arrangement in which the exhaust valve was parallel to the bore with the intake valve tipped toward the intake manifold (the classic polyspherical chamber).  For the LA, Chrysler rendered all the valves tipped to the intake manifold and in-line (as viewed from the front), the industry’s standard approach to a wedge combustion chamber.  The reason for the change was that the decision had been taken to offer the compact Valiant with a V8 but it was a car which had been designed to accommodate only a straight-six and the wide-shouldered polyspheric head A-Series V8s simply wouldn’t fit.  So, essentially, wedge-heads were bolted atop the old A-Series block but the “L” in LA stood for light and the engineers wanted something genuinely lighter for the compact (in contemporary US terms) Valiant.  Accordingly, in addition to the reduced size of the heads and intake manifold, a new casting process was developed for the block (the biggest, heaviest part of an engine) which made possible thinner walls.  "Light" is however a relative term and the LA series was notably larger and heavier than Ford's "Windsor" V8 (1961-2000) which was the exemplar of the "thin-wall" technique.  This was confirmed in 1967 when, after taking control of Rootes Group, Chrysler had intended to continue production of the Sunbeam Tiger, by then powered by the Ford Windsor 289 (4.7 litre) but with Chrysler’s 273 LA V8 substituted.  Unfortunately, while 4.7 Ford litres filled it to the brim, 4.4 Chrysler litres overflowed; the Windsor truly was compact.  Allowing it to remain in production until the stock of already purchased Ford engines had been exhausted, Chrysler instead changed the advertising from emphasizing the “…mighty Ford V8 power plant” to the vaguely ambiguous “…an American V-8 power train”.

322 cubic inch Nailhead in 1953 Buick Skylark convertible (left) and 425 cubic inch Nailhead in 1966 Buick Riviera GS (with dual-quad MZ package, right).  Note the “Wildcat 465” label on the air cleaner, a reference to the claimed torque rating, something most unusual, most manufacturers using the space to advertise horsepower or cubic inch displacement (CID).

The nailhead wasn’t ideal for producing top-end power but the design did generate prodigious low-end torque, something much appreciated by Buick's previous generation of buyers who much had relished the low-speed responsiveness of the famously smooth straight-8.  However, like everybody else, Buick hadn’t anticipated that as the 1950s unfolded, the industry would engage in a “power race”, something to which the free-breathing Cadillac V8s and Chrysler’s Hemis were well-suited.  For that, the somewhat strangulated Buick Nailhead was not at all suited and to gain power the engineers were compelled to add high-lift, long-duration camshafts which enabled the then magic 300 HP (horsepower) number to be achieved but at the expense of smoothness; tales of Buick buyers (long accustomed to straight-8s that ran so smoothly at idle it could be hard to tell if the things were running) returning to the dealer to fix the “rumpity-rump” became legion.  Still, the Nailhead was robust, relatively light and offered what was then a generous displacement and the ever inventive hot-rod community soon worked out the path to power was to use forced induction and invert the valve use, the supercharger blowing the fuel-air mix into the combustion chambers through the exhaust ports while the exhaust gases were evacuated through the larger intake ports.  Thus, for a while, the Nailhead enjoyed a role as a niche player although the arrival in the mid 1950s of the much more tuneable Chevrolet V8s ended the vogue for all but a few devotees who continued use well into the 1960s.  Buick acknowledged reality and, unusually, instead of following the industry trend and drawing attention to displacement & power, publicized their big torque numbers, confusing some (though probably not Buick buyers who were a loyal crew who sometimes would look down on more expensive Cadillacs because they were "flashy").  The unique appearance of the old Nailhead retains some nostalgic appeal for the modern hot-rod community and they do sometimes appear, a welcome change from the more typical small-block Fords or Chevrolets.

Lockheed SR-71 Blackbird (1964-1999).

Not confused about numbers was the USAF (United States Air Force) which was much interested in power for its aircraft but also had a special need for torque on the tarmac and briefly that meant another quirky niche for the Nailhead.  The Lockheed SR-71 Blackbird (1964-1979) was a long-range, high-altitude supersonic (Mach 3+) aircraft used by the USAF for reconnaissance between 1966-1998 and by the NASA (National Aeronautics & Space Administration) for observation missions as late as 1999.  Something of a high-water mark among the extraordinary advances made in aeronautics and materials construction during the Cold War, the SR-71 used Pratt & Whitney J58 turbojet engines which featured an innovative, secondary air-injection system for the afterburner, permitting additional thrust at high speed.  The SR-71 still holds a number of altitude and speed records and Lockheed’s SR-72, a hypersonic unmanned aerial vehicle (UAV) is said to be in an “advanced stage” of design and construction although whether any test flights will be conducted before 2030 remains unclear, the challenges of sustaining in the atmosphere velocities as high as Mach 6+ onerous given the heat generated and stresses imposed by the the fluid dynamics of air at high speed.

Drawing from user manual for AG330 starter cart (left) and AG330 starter cart with dual Buick Nailhead V8s (right).

At the time, the SR-71 was the most exotic aircraft on the planet but during testing and early in its career, just for the engines to start it relied on a pair of even then technologically bankrupt Buick Nailhead V8s.  These were mounted in a towed cart and were effectively the turbojet’s starter motor, a concept developed in the 1930s as a work-around for the technology gap which emerged as the V12 aero-engines became too big to start by hand but lacked on-board electrical systems to trigger ignition.  The two Nailheads were connected by gears to a single, vertical drive shaft which ran the jet up to the critical speed at which ignition became self-sustaining.  The engineers chose the Nailheads after comparing them to other large displacement V8s, the aspect of the Buicks which most appealed being the torque generated at relatively low engine speeds, a characteristic ideal for driving an output shaft, torque best visualized as a "twisting" force.  After the Nailhead was retired in 1966, later carts used Chevrolet big-block V8s but in 1969 a pneumatic start system was added to the infrastructure of the USAF bases from which the SR-71s most frequently operated, the sixteen-cylinder carts relegated to secondary fields the planes rarely used.

Sanpaku

Sanpaku (pronounced san-pach-ew)

An eye in which the sclera (white of the eye) is visible on three sides of the iris rather than the usual two (left & right).

Pre 1700s: A borrowing from the Japanese 三白 (sanpaku) (three whites) or 三白眼 (sanpaku gan) (three-white eyes).  Sanpaku is a noun and sanpakuish is an adjective; the noun plural is sanpakus.

Sanpaku (三白) (three whites) & Sanpaku gan (三白眼) (three-white eyes) are Japanese terms from traditional Chinese & Japanese medicine and they describe the “condition” in which the white of the eye is visible either above or below the iris when looking straight ahead.  Although the word was popularized by Japanese educator and nutritionist Nyoichi “George” Ohsawa (1893–1966) when he published the book You Are All Sanpaku in 1965, the idea had existed in oriental medicine probably for centuries although it’s impossible accurately to determine its origin.  It was mentioned in the diaries of at least one nineteenth century US Navy physician but attracted no interest in the West until the release of Ohsawa san’s book.  In Western medicine the phenomenon is described as “lower scleral show” or “inferior scleral show”, terms which are merely descriptive because (1) it’s something thought within the range of normality, (2) is indicative of no other mental or physical states and thus (3) is generally not considered a medical condition requiring treatment and is attributed variously to (3a) normal variation in eyelid anatomy, (3b) transient facial expression or gaze direction, (3c) traumatic injury or (3d) age-related tissue changes.  There are orbital or eyelid conditions (the best known being a thyroid-related eye disease causing lid retraction) which can induce a sanpaku-like appearance but instances are vanishingly rare.  In short, the medicalization of sanpaku is thought a product of superstition so predictably, on social media, sanpaku eyes seem to have a cult following.

Sydney Sweeney (b 1997) displaying her Sanpaku inferior (sclera (white of the eye) visible below the iris), Met Gala, Metropolitan Museum of Art, Manhattan, New York City, May 2025.  Lovely though her eyes are, it may be not many have long focused on them.

In You Are All Sanpaku, Ohsawa san described sanpaku as a condition which indicated physical and mental imbalances and discussed its significance in relation to diet and overall well-being.  Historically, sanpaku is believed to have entered oriental medicine from the Japanese practice of “face-reading” and those with eyes observed thus were considered ill-fated and destined for a life filled with misfortune, culminating often with an early demise.  It gained a following on social media by the usual means: celebrity association.  Diana, Princess of Wales, President John Kennedy & Marilyn Munroe, all of whom died young, were all sanpakus and as Ohsawa san warned in You Are All Sanpaku: the eyes indicate someone's fate, signifying imminent danger or an “early and tragic end.”

Diana, Princess of Wales (1961-1997, far left), Marilyn Monroe (1926–1962, centre left), Billie Eilish (b 2001. centre right) and John Kennedy (JFK, 1917–1963; POTUS 1961-1963, far right).  Three died young in tragic circumstances but Ms Eilish remains fit and well.

The original basis of “face reading” isn’t known but as a diagnostic tool it focused on the matter of “balance”, something important also to the physicians of Antiquity who identified the “four humors”: flegmat (phlegm), sanguin (blood), coleric (yellow bile) & melanc (black bile) which were the causative agents of the four personality types, the phlegmatic, the sanguine, the choleric & the melancholic.  In the East, signs of sanpaku meant a man’s whole system (physical, physiological and spiritual) was out of balance, something caused by sins committed against the order of the universe, accounting for his sickness, unhappiness or insanity.  Ohsawa san noted that in the West, such folk had come to be called “accident prone” and they were the ones who should take note of the warning from sanpaku, nature’s tap on the shoulder.  A practical author of self-help texts, Ohsawa san recommended sanpaku eyes should be treated with a macrobiotic diet, focusing on brown rice and soybeans, something on which he had real expertise as the founder of the macrobiotic diet.

By their sanpaku you shall know them: Adolf Hitler (1889-1945; Führer (leader) and German head of government 1933-1945 & head of state 1934-1945, left), crooked Hillary Clinton (b 1947; US secretary of state 2009-2013, centre) and cult-leader Charles Manson (1934-2017, right).

Interestingly, the beliefs about sanpaku are culturally variable although universally it’s held the condition determines one's fate.  In the Japanese tradition those consequences are ill fate and misfortune while the Chinese associate sanpaku with good luck and wealth and this divergence has interested cultural anthropologists who study the symbolism and mythologies of different societies.  The tradition divides the eyes into "yin sanpaku" and "yang sanpaku", the roots of this the ancient Chinese concept of yin & yang, representing the duality of opposing yet complementary forces in the universe.  Yin and Yang are fundamental concepts in Chinese philosophy and represent complementary and interconnected aspects of the universe. Yin is associated with qualities such as darkness, femininity, passivity, and coldness, while Yang is associated with light, masculinity, activity, and warmth. They’re seen as opposing forces that are in a constant state of dynamic balance and they exist within all phenomena, including human physiology, nature and society.  In this they differ from the (wholly un-related) concept in particle physics of matter and anti-matter.  Matter is the familiar stuff which is much of the physical universe (particles such as protons, neutrons, and electrons) while anti-matter consists of particles with the same mass as their matter counterparts but carrying an opposite charges.  When matter and anti-matter particles come into contact, they can annihilate each other, releasing energy.  Ying and Yang, mutually dependent, live in peaceful co-existence.

The Mean Girls (2004) crew demonstrate the range:  Rachel McAdams (b 1978, far left) & Lindsay Lohan (b 1986, centre-left) are in the part of the population who are either not sanpakus or the effect is imperceptible.  Lacey Chabert (b 1982, centre-right) is in the group with a separation around 1 mm while Amanda Seyfried (b 1985, far right) displays up to 2 mm depending on her expression.

A quadrilateral meeting to discuss German war guilt reparations and allied debts accumulated during World War I (1914-1918): Raymond Poincaré (1860–1934; President of France 1913-1920, far left), Andrew Bonar Law (1858–1923; Prime Minister of the United Kingdom 1922-1923, centre-left), Benito Mussolini (1883-1945; Duce (leader) & Prime-Minister of Italy 1922-1943, centre right) and Georges Theunis (1873–1966; Prime Minister of Belgium 1921-1925 & 1934-1935, far right), 10 Downing Street, London, December 1922.

Before it became a meme, this was an obscure photograph which until the twenty-first century had appeared only in some specialist history texts but as the internet achieved critical mass, memes became a thing and Mussolini’s sanpaku eyes were a gift for the meme-makers, most captions suggesting the Duce may have had a sudden premonition of his own unfortunate end although others offered: “I feel naked without a moustache”, “I think I have imposter syndrome”, “Oh God, I just pooped my pants”, “I know one of these men is a Freemason but I don't know which” and “I wonder if they can tell I've smoked some weed”.  However, although not noted as a mystic, he may have sensed another's impending death, “sitteth at the right hand”, Andrew Bonar Law then having only months to live.

A colorized image of the lovely Hedy Lamarr (stage name of Hedwig Eva Maria Kiesler, 1914-2000).  Bare shoulders and sanpaku eyes have an allure.

Once best known as a Hollywood film star, Ms Lamar’s twenty-first century fame comes from her contribution early in World War II (1939-1945) to an early version of “jamming-resistant” radar-guidance.  The idea came to her while playing an ad-hoc piano duet with a composer as they attempted a synchronized “note-hopping” piece, something used in avant-garde compositions but effected mechanically by recording four “player pianos” (instruments modified with electromechanical or pneumatic mechanisms that activated the keys by instruction from perforated paper or metallic rolls) fitted with matching rolls.  From this example, the pair came to understand radio frequencies also could be switched, the wartime utility being this would make signals less susceptible to being jammed.  Even then, “frequency hopping” was not a new idea but the implementation Ms Lamar suggested was sufficiently novel to be granted a patent although the technology didn’t then exist to minimize sufficiently the size of the components which could be used in torpedos or rockets so use of the concept didn’t become widespread until the 1960s.  The “spread spectrum” later became familiar in WiFi and secure networking.

Princess Beatrice, Mrs Edoardo Mapelli Mozzi (b 1988).  Until she appeared at a royal wedding in the fascinator she made famous (some humorless souls would have said infamous), she was most noted for her lovely sanpaku eyes.

In Japanese face reading, yang sanpaku eyes (white part visible above the iris) reveal a person's dark and sinister nature, the eyes indicating the unstable mental state suffered by individuals exhibiting uncontrollable aggression, such as psychopathic murderers or serial killers.  Yin Sanpaku Eyes (sclera visible below the iris) signify a different physical or mental imbalance, one caused by the abuse of drugs, alcohol, and sugar which disrupt the body's equilibrium.  Although discouraged by all in the profession except the odd, entrepreneurial cosmetic surgeon, treatment options are available to “correct” scleral show and the most effect treatment is aesthetic plastic surgery, specifically the procedure called blepharoplasty, which can correct the appearance of the eyes.  The construct of blepharoplasty was blepharo- +‎ -plasty.  Blepharo- was from the New Latin, from the Ancient Greek βλέφαρον (blépharon) (eyelid; a feature resembling an eyelid) and -plasty was from the Ancient Greek πλαστός (plastós) (molded, formed) which now has the special meaning in medicine meaning "repair, restoration or re-shaping of part of the body with a surgical procedure".

Alexandria Ocasio-Cortez (AOC, b 1989, US Representative (Democrat-New York) since 2019 and one of "the squad") displaying her Sanpaku superior (sclera visible above the iris).  Some other of her body parts are also well-documented.

Casual observation suggests sanpaku eyes are far from rare and there are said to be three classes: (1) those with at least a .25 mm (.0098 inch) space between the iris and the upper and lower eyelids, (2) those with a separation of 1 (.0394 inch) mm and (3) those with a gap of 2 mm (.0787 inch) or more.  The concition need not manifest as something symmetrical (in the vertical axis), the two elements being (1) Sanpaku inferior: white visible below the iris and (2) Sanpaku superior: white visible above the iris, the latter said often induced when a subject is frightened or physiologically stressed).  However although “estimates” have been published, neither the prevalence of the condition nor the distribution within the three (unofficial) groups have ever been the subject of a reputable epidemiological study; because “sanpaku eyes” is not a recognised medical or anthropometric category; funding would thus be hard to secure although, as a purely observational and statistical exercise, presumably not many ethics departments would much be troubled.  So, lacking a defined diagnostic entry, there is no standardised measurement threshold and estimates of prevalence are thus almost certainly speculative and thus unreliable.  Those with sanpaku eyes should not too much dwell on the numbers and instead flutter their eyelashes and enjoy the admiring glances.

Mean Girls four-way phone call: Eye-rolls (Amanda Seyfried, top right) don't count, a sanpaku defined only by separation maintained when looking ahead or to the side.

Humans are not the only species with a sclera but we are untypical in it being so visible.  That humans even have white scleras has interested linguistic anthropologists, evolutionary biologists and other researchers, some offering the Cooperative Eye Hypothesis which suggested the distinctive appearance evolved as a mechanism with non-verbal communication could be enhanced.  According to this conjecture, the high visibility of the iris & pupil against the white background allows an interlocutor more easily to track eye movements, helping individuals to understand where others are looking during interactions.  Observational studies revealed the way humans and other great apes move their heads and eyes in different ways, humans relying more on eye movements than head movements to see where someone else is looking.  Apes, without the white component in their eyes, tend more to move the whole head.  Not all support the "cooperative eye" faction but it’s an interesting approach to understanding the evolutionary significance of the human eye's appearance and the sophistication of communication is certainly a noted difference between humans and apes.

Seeing the whites of the eye: a gree-eyed cormorant taking lunch.

The phrase “don’t shoot until you see the whites of their eyes” comes of the military and was an instruction to infantry in the age of the musket to delay firing until the target was within close range, the rationale being (1) accuracy would be enhanced and (2) the projectile (musket ball) would strike with greater energy, thus increasing the effectiveness (measured in the casualty & death rates).  It’s often attributed to Colonel William Prescott (1726–1795) shouting it to his troops at the Battle of Bunker Hill (1775) during the American Revolutionary War (1775-1783) but according to Phrase Finder, the origins lie at least 32 years earlier.  On 27 Jun, 1743, during the Battle of Dettingen (fought in Bavaria as one of the "footnote engagements" of the War of the Austrian Succession (1740-1748)), the resourceful Scot Lieutenant-Colonel (later Lieutenant General) Sir Andrew Agnew of Lochnaw (1867-1761) 5th Baronet) departed from military orthodoxy when, responding to a French cavalry charge, adopted a novel tactic he’d devised, keeping his men not in the conventional square formation to meet the charge head on but having the two centre companies divide from the centre, falling back from the outer markers, thereby compelling the French to gallop through a withering crossfire.  It was potentially a high-risk strategy but he’d trained his troops well the French cavalrymen obediently threaded the needle, suffering heavy losses.  Tacitly acknowledging the danger presented by his innovation, Sir Andrew’s succinct instruction to his brigade had been: “Dinna fire till ye can see the whites of their e' en . . . if ye dinna kill them they'll kill you.”

If the human eye lacked a white sclera it would mean the “messaging” in facial expressions (a non-verbal clue in communication) would have evolved a little differently; Paris Hilton (b 1981) illustrates (digitally altered image).  Ms Hilton has brown eyes but often wears blue contact lens.

As far as is known, all living creatures on Earth came ultimately from a single event which can be said to be the origin of life because at this time, there is no evidence of other living things anywhere in the universe.  Everything else is speculative; life may have started (or arrived) here many other times but for whatever reason not thrived and around the universe there may be many forms of life; some may be more advanced than us or we may be unique in our scientific and technological mastery.  The single point of origin is why we share elements of DNA (Deoxyribonucleic acid, the so-called “building-blocks of life”) with our cats, dogs, goldfish and bananas so, unsurprisingly, in living creatures, eyes are common, often in pairs but unlike those in humans, not all are out-growths of a brain although, in many of the lineages of the Metazoa they are neurally derived and remain tightly integrated with the central nervous system.

A nice pair of boobies.  Charmingly, blue-footed boobies are known to be monogamous, pairs often staying together for life.  Like us, birds are two eyed vertebrates although except for the old outlier (like owls) their eyes, for good reasons, shifted to the sides.  Note how the booby’s eye differs from that of a human.

As a general principle it all depended on the developmental origin and phylogeny (the evolutionary history of groups of organisms).  In vertebrates (mammals, birds, fish etc), the eye evolved as an evagination (a growth outward) of the forebrain during embryogenesis (the process by which an embryo is formed and develops).  Cephalopods (octopus, squid etc) differ in that while the optic lobes of the brain are large and closely connected, the eye is not literally a brain protrusion; thus, while neurally integrated, the eyes are not brain outgrowths.  Arthropods (insects, crustaceans and such) have compound eyes formed from ectodermal (of the The outermost of the three tissue layers in the embryo of a metazoan animal) tissues which connect to the brain via optic nerves and are thus also neurally connected but not developmental extensions of the brain itself.  Many cnidarians (such as the box jellyfish) possess complex lens eyes but lack a centralized brain, their eyes peripheral sensory structures connecting to nerve rings rather than a true brain.  Many invertebrates have relatively simple photoreceptors which can be thought of as “eyespots” which can be distributed across body tissues, the best contemporary comparison probably the sensors now so ubiquitous in electronic devices.

Boobies, one step at a time.

A booby is a seabird in the genus Sula, part of the Sulidae family.  Boobies are closely related to the gannets (Morus), which were formerly included in Sula, the genus created in 1760 by the French naturalist Mathurin Jacques Brisson (1723-1806).  The name was derived from súla, the Old Norse and Icelandic word for the other member of the family Sulidae, the gannet.  The English name booby was based on the Spanish bobo (stupid) as the tame birds often landed on board sailing ships, where they were easily captured and eaten.  As well as a popular addition to the diet of sailors for whom meat other than fish was a rarity, it was fortuitous for many, the Admiralty's archives revealing boobies often mentioned as having been caught and eaten by shipwrecked sailors.

Mr Andrew Mountbatten Windsor in police car, under arrest, February, 2026.

If humans had eyes free of a white sclera (like the booby and many birds), our appearance would be quite different, illustrated by a digitally edited image of a green-eyed (former prince/duke/admiral etc) Andrew-Mountbatten Windsor (b 1960), rendered as a line drawing by Vovsoft.  However, the use of that image to demonstrate the point may not have been the best choice because, in the original, his expression didn’t appear greatly different.

As well as charming eyes, boobies also have interesting feet.  The distinctive blue feet (the result of pigments ingested from their diet of fish) also play a part in the bobby’s mating ritual although not exactly in the podophilic sense familiar in a sub-set of humans.  In the spring mating season, the bird’s feet become a bright turquoise blue and, to demonstrate their health and vitality, conspicuously they will display them to potential partners.  The job done, as their eggs hatch, the blue hue fades to something less vivid.  One aspect of their behaviour which amused the ornithologists who first observed it was that if among fishers unloading their catch, it tossed a small fish from the by-catch, a booby will take it and waddle off somewhere to enjoy it in solitude rather than gulping it down as in common in many species.  Like penguins, although ungainly on land, they are skilled plunge divers which used their streamlined bodies and air sacs “fly” through the water, catching their prey at high speed and they hunt in "packs", coordinating their movement to maximize the catch.  Boobies have been recorded diving from as high as 90 m (300 feet), their speed upon entry estimated at around 100 km/h (60 mph).