See Like Animals Open the tool
Menu

Lowland paca vision: the science and the numbers

Cuniculus paca · order Rodentia · Mammals: all the numbers

Its sharpest vision resolves 2.8 cycles per degree, against 63.75 for people in this dataset.[6] Its activity pattern is nocturnal.[14][15][16][17][18]

See it on your photoBack to How does the lowland paca see?
  • 2.8cycles per degree (sharpness)Measured

The lowland paca (Cuniculus paca) is a mammal in the order Rodentia. Its eyes belong to the vision type Small prey mammal (UV): two or three cone types, often including ultraviolet, low sharpness and a near-panoramic field. Measured in this species: sharpness, foveas and night vision. Measured core: measured values on at least 3 of the 6 dials.

This is a simulation built from published eye measurements, not what the animal experiences.

Method: How we know what animals see (the See Like Animals vision engine) · Sources · Last updated . Every value below carries its evidence level and sources; nothing is typed by hand.

What the lowland paca sees: colour receptors

Lowland paca colour receptor peaks, 300 to 700 nmLowland paca: 2 receptor peaks at 400, 530 nm; you: 3 at 421.5, 532, 558.4 nm. ultraviolet300400500600700
Lowland paca: 400, 530 nmPeople: 421.5, 532, 558.4 nmWavelength in nanometres

What stands out

  • Its sharpest vision resolves 2.8 cycles per degree: the finest stripe pattern it can tell apart from grey.
  • Activity pattern: nocturnal.

The six dials

Evidence levels: how the tiers work. "Measured" means a value measured in this species; "Estimated" values come from a close relative or an eye-size formula. The last column gives the values for people from the same catalogue.

Vision values for the lowland paca (Cuniculus paca), catalogue-v1
DialValueEvidenceSourcesPeople
ColourColour receptors
2 receptor classes: 400 nm (VS/SWS (violet)), 530 nm (MWS (green))
receptor set of nearest measured relative Cavia porcellus (same order Rodentia)
Group default[1][2]Colour receptors: 3 receptor classes: 421.5 nm (VS/SWS (violet)), 532 nm (MWS (green)), 558.4 nm (LWS (long)) Measured (not re-verified)[1][3][4][5]
SharpnessAcuity
2.8 cycles per degree
median of 1 anatomical-ganglion rows (method priority rule)
Measured[6]Acuity: 63.75 cycles per degree Measured[7][6]
Field of viewBinocular overlap
52°
median of 15 relatives in order Rodentia: Octodon degus, Octodon lunatus, Rattus rattus, Mus musculus, Mesocricetus auratus, Sciurus carolinensis
Group default[8][9][10][11]Binocular overlap: 122.5° Measured[8][9]
Total field of view: 200° Measured (not re-verified)[12]
Blind area behind the head: 160° Derived[12]
Eye placement: frontal Derived[8][9]
Sharp zones (foveas)Number of foveas
0
fovea_present / area_centralis_type (retinal topography; count 1 = fovea present, 0 = none)
Measured[13]Number of foveas: 1 Measured[13]
Fovea type: fovea Measured[13]
Fovea type
horizontal streak		Measured[13]
Night visionActivity pattern
nocturnal
mode of 6 rows (of 6 rows): nocturnal
Measured (not re-verified)[14][15][16][17][18]Activity pattern: diurnal Measured (not re-verified)[14][19][15][1][16][17][20][18]
Pupil shape: vertical Group default[21][22]
Reflective layer (tapetum): no Measured[23]
Rods vs cones: cone-dominated Derived[14][19][15][1][16][17][20][18]
Rods vs cones
rod-dominated
nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated
Derived[14][15][16][17][18]
Motion (flicker fusion)Flicker fusion frequency
62.5 Hz
median of 7 relatives in order Rodentia: Rattus norvegicus, Cavia porcellus, Mus musculus, Callospermophilus lateralis, Tamias amoenus, Tamiasciurus hudsonicus
Group default[24][25][26][27]Flicker fusion frequency: 60 Hz Measured[25][26]

All mammals side by side: Mammals: every measurement. Method: how we know what animals see.

Sources

  1. Longcore 2023
  2. VPOD in-vivo (MSP / single-cell) lambda… 2025
  3. Kirwan
  4. Müller et al. 2009
  5. Thermal Activation and Photoactivation of Visual… 2004
  6. Veilleux et al. 2014
  7. Kirk et al. 2004
  8. Heesy 2004
  9. Heffner et al. 1992
  10. Vega-Zuniga et al. 2013
  11. Vega-Zuniga et al. 2017
  12. Campbell & Green 1965
  13. Kopania et al. 2025
  14. Anderson et al. 2017
  15. Wilman et al. 2014
  16. Maor et al. 2017
  17. Jones et al. 2009
  18. Moura et al. 2024
  19. Borges et al. 2018
  20. Schmitz et al. 2011
  21. Banks et al. 2015
  22. Cervino et al. 2021
  23. Guareschi et al. 2025
  24. Haarlem et al. 2026
  25. Healy et al. 2013
  26. Inger et al. 2014
  27. Lafitte et al. 2022

Every value cites its sources (all sources). Values were extracted from these works and converted (units, medians, derived values); changes are ours, and the listed sources do not endorse this site. Data: catalogue-v1, built 2026-09-29. Accuracy notes: how accurate is this? Method: how we know.