Human eyeball
The human eyeball is the globe-shaped organ that receives light and begins the process of vision. The optic nerve carries visual signals to the brain.
Also known as: eye globe, human eye
How big is it?
2.4 cm · representative globe diameter
Also 0.9449 in
Representative globe diameter · representative
Typical recorded range: 2.3 cm to 2.5 cm.
A little perspective
Human eyeball vs US quarter: diameter comparison
The diameter of a US quarter is about 1.01 times the globe diameter of the human eyeball.
The human eyeball is the globe-shaped organ that receives light and begins the process of vision.
A US quarter is a coin worth twenty-five cents, commonly used in United States currency.
Both rulers start at the same zero and share one linear scale. Artwork keeps its original proportions.
Measurements, assumptions & sources +
Human eyeball
Representative globe diameter: 2.4 cm; representative; range 2.3 cm–2.5 cm.
A representative adult human eye globe about 24 mm across. The corneal bulge and optic nerve are contextual and excluded from the calibrated globe diameter.
Encyclopaedia Britannica — Human eye
The marked representative globe diameter is calibrated. Unmeasured illustration details are representative.
US quarter
Diameter: 2.426 cm; specified.
Standard copper-nickel clad US quarter: 24.26 mm diameter, 1.75 mm thickness and 5.67 g mass. Earlier silver quarters do not share this mass. The illustrated relief is representative; the circular rim is the measured span.
US Mint — circulating coin specifications
The marked diameter is calibrated. Unmeasured illustration details are representative.
Use the visual comparison to explore its scale, then check the measurements and sources.
Change your perspective
Put it next to…
Choose a suggestion to redraw the comparison, or open its page to learn what it is.
Why this measurement?
Why we use 2.4 cm
We compare the globe diameter of the human eyeball. This is a representative comparison value; individual specimens or conditions can vary. The recorded range is 2.3 cm to 2.5 cm.
A representative adult human eye globe about 24 mm across. The corneal bulge and optic nerve are contextual and excluded from the calibrated globe diameter.
The marked horizontal span follows the measured feature, not the edges of the image. How calibrated comparisons work →
Recorded properties
Dimensions and measurements
| Property | Selected value | Recorded range | Basis |
|---|---|---|---|
| 2.4 cm | 2.3 cm to 2.5 cm | representative |
Around this scale
Explore nearby values.
Compare examples with lower, similar and higher values. Each card names the measurement being compared.
Nearest lower valueEveryday objects£1 coin2.343 cmSpecified maximum diameterA £1 coin is a twelve-sided British coin used as standard currency in the United Kingdom.
Around the same scaleEveryday objectsCacao bean2.4 cmDefined dry-bean lengthA cacao bean is the dried seed of the Theobroma cacao tree, used to produce cocoa and chocolate.
Nearest higher valueEveryday objectsUS quarter2.426 cmDiameterA US quarter is a coin worth twenty-five cents, commonly used in United States currency.Sources and method
Want to check the number?
The source records and measurement method remain available for inspection.
- Encyclopaedia Britannica — Human eyeThe adult eye globe is approximately 24 mm in diameter; anatomy varies by person and axis.
There’s always another scale
Follow your curiosity.
PeopleHuman1.75 mA human is a primate of the species Homo sapiens, distinguished by habitual upright walking, language and complex tool use.Everyday thingsUS quarter2.426 cmA US quarter is a coin worth twenty-five cents, commonly used in United States currency.
Living thingsSea angel2 cmA sea angel is a small, transparent swimming sea slug with wing-like appendages, found in cold ocean waters.
Everyday thingsUK 10p coin2.45 cmA UK 10p coin is the ten-pence denomination of the decimal pound sterling circulation coinage.
SportSquash ball4 cmA squash ball is a small, hollow rubber ball used in the sport of squash.Everyday things£1 coin2.343 cmA £1 coin is a twelve-sided British coin used as standard currency in the United Kingdom.
PeopleFingernail1.5 cmA fingernail is the hard, protective covering at the tip of a human finger, composed of keratin.
Living thingsBird’s nest fungus2 cmBird’s nest fungus is a small fungus whose fruiting body resembles a tiny nest containing spore-filled capsules called peridioles.