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Firefly vision: the science and the numbers

Photinus pyralis · order Coleoptera · Insects: all the numbers

The firefly has 2 colour receptor classes (375 and 570 nm), one of them in the ultraviolet.[1][2] The firefly stops seeing flicker at 40 Hz, against 60 Hz for people.[25]

See it on your photoBack to How does the firefly see?
  • 2colour receptor classesMeasured
  • 40hertz flicker fusion (motion)Measured

The firefly (Photinus pyralis) is an insect in the order Coleoptera. Its eyes belong to the vision type Bee, ant and locust UV trichromat: three receptor types (ultraviolet, blue and green, no red), a low-resolution compound eye and fast motion vision. Measured in this species: colour, night vision and motion (flicker fusion). 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 firefly sees: colour receptors

Firefly colour receptor peaks, 300 to 700 nmFirefly: 2 receptor peaks at 375, 570 nm; you: 3 at 421.5, 532, 558.4 nm. ultraviolet300400500600700
Firefly: 375, 570 nmPeople: 421.5, 532, 558.4 nmWavelength in nanometres

What stands out

  • It has two colour receptor classes (a dichromat): reds and greens fall on one axis, as in red-green colour blindness in people.
  • It stops seeing flicker at 40 Hz, against 60 Hz for people in this dataset, so fast motion looks choppier to it.[26][27]
  • 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 firefly (Photinus pyralis), catalogue-v1
DialValueEvidenceSourcesPeople
ColourColour receptors
2 receptor classes: 375 nm (UVS), 570 nm (LWS (long))
measured in this species
Measured[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]
Ultraviolet
yes: at least one receptor peaks in the ultraviolet		Measured
SharpnessAcuity
0.28 cycles per degree
median of 2 relatives in family Lampyridae: Photuris versicolor, Photuris quadrifulgens
Estimated[6][7]Acuity: 63.75 cycles per degree Measured[8][9]
Angle between facets
1.8°
median of 1 relatives in family Lampyridae: Photuris versicolor
Estimated[6]
Eye type
compound eye
Field of viewNo value in the catalogue.Binocular overlap: 122.5° Measured[10][11]
Total field of view: 200° Measured (not re-verified)[12]
Blind area behind the head: 160° Derived[12]
Eye placement: frontal Derived[10][11]
Sharp zones (foveas)Number of foveas
0
median of 91 relatives in class Insecta: Empis prodromus, Rhamphomyia albidiventris, Rhamphomyia breviventris, Rhamphomyia maculipennis, Rhamphomyia marginata, Rhamphomyia murina
Group default[13]Number of foveas: 1 Measured[14]
Fovea type: fovea Measured[14]
Fovea type
none		Group default[13]
Night visionActivity pattern
nocturnal
mode of 1 rows (of 1 rows): nocturnal
Measured[1]Activity pattern: diurnal Measured (not re-verified)[15][16][17][1][18][19][20][21]
Pupil shape: vertical Group default[22][23]
Reflective layer (tapetum): no Measured[24]
Rods vs cones: cone-dominated Derived[15][16][17][1][18][19][20][21]
Rods vs cones
no rods (invertebrate photoreceptors)
nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated
Derived[1]
Motion (flicker fusion)Flicker fusion frequency
40 Hz
median of 1 rows (no bright-light flag) (behavioural/whole-eye ERG rows; all rows: [40.0])
Measured[25]Flicker fusion frequency: 60 Hz Measured[26][27]

All insects side by side: Insects: every measurement. Method: how we know what animals see.

Sources

  1. Longcore 2023
  2. van der Kooi CJ, Stavenga DG… 2021
  3. Kirwan
  4. Müller et al. 2009
  5. Thermal Activation and Photoactivation of Visual… 2004
  6. Caves et al. 2018
  7. AndrewPMeade/FabricTools, sciphy/data_utils/datas… 2021
  8. Kirk et al. 2004
  9. Veilleux et al. 2014
  10. Heesy 2004
  11. Heffner et al. 1992
  12. Campbell & Green 1965
  13. Comparative data for dance fly eye…
  14. Kopania et al. 2025
  15. Anderson et al. 2017
  16. Borges et al. 2018
  17. Wilman et al. 2014
  18. Maor et al. 2017
  19. Jones et al. 2009
  20. Schmitz et al. 2011
  21. Moura et al. 2024
  22. Banks et al. 2015
  23. Cervino et al. 2021
  24. Guareschi et al. 2025
  25. Haarlem et al. 2026
  26. Healy et al. 2013
  27. Inger et al. 2014

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.