How they see
How does a duck see the world?
UV vision, and eyes nearly all around
A duck watches the world through ultraviolet-tuned, four-colour eyes set wide on its head, giving it a near-complete circle of awareness. That panorama lets it feed, court and watch for danger almost all at once, while ultraviolet reveals plumage signals on other ducks that stay hidden from us. Water, sky and rival are all read in richer colour than we manage.
See through their eyes
Human ≈ 60 cpd (20/10)
How sharp is a duck's vision?
Its eyes resolve about 10 cycles per degree (20/60 (est.)), while a human reaches around 60 cpd (20/10). Its field of view spans about 340°.
How does a duck see a human?
Its eyes resolve about 10 cycles per degree against your 60, so a face has to be roughly 6 times closer for it to pick out the detail you do. Your outline and your movement read clearly; your expression does not.
Colour comparison
How each colour shifts when seen through this animal's eyes, using the same colour model as the app. Tones a screen can't emit (such as ultraviolet) are shown as an approximation.
What colours can a duck see?
Rich colour plus ultraviolet; UV highlights plumage signals.
Photoreceptors
Tetrachromat (4 cones) + oil droplets
Cone peak sensitivities
- UV415 nm
- S (blue)450 nm
- M (green)505 nm
- L (red)570 nm
How does a duck see in the dark?
Reasonable; more day-active.
How does a duck's vision compare to a human's?
A duck's detail runs around 20/60 to your 20/20, but it sees a fourth colour and ultraviolet you cannot, sweeping a 340-degree field against your 200.
What is special about a duck's vision?
- Sees ultraviolet
- Near-360° field
- Can sleep with one eye open (one hemisphere awake)
What the research shows
Most of what is known about mallard colour vision comes from microspectrophotometry, which measures the light absorbed by individual cells taken from a retina. Jane & Bowmaker (1988) used it to identify four classes of single cone and the coloured oil droplets that sit in front of them. Three of those droplets act as cut-off filters, narrowing the band each cone responds to, while the shortest-wavelength cone carries a transparent droplet, which is what lets it reach into the violet and near-ultraviolet. The longest-wavelength cone peaks near 570 nm. Hart (2001) places this arrangement of droplet-filtered single cones within the general pattern found across birds.
Spatial detail is far less certain than colour. The figure of roughly 8–12 cpd is an estimate rather than a grating measurement, and the simulation uses 10 cpd, about 20/60. Flicker fusion is estimated even more loosely, at around 70–100 Hz. A screen simulation runs into three hard limits with this species: it cannot display the near-ultraviolet that the short cone responds to, so any violet highlight is only a stand-in; it cannot add the fourth colour dimension that four cone classes create; and it cannot show a 340-degree panorama on a flat, forward-facing display without distorting it.
Guides: Animals that see ultraviolet · Which animal has the best eyesight? · All guides
Scientific sources
- Jane & Bowmaker (1988)
- Hart (2001)
Download Animal Vision
Point your camera at anything and watch the world transform into this animal’s vision in real time.
