How does the red-eared slider see?
The red-eared slider (Trachemys scripta) is a reptile in the order not recorded. Its eyes belong to the vision type Diurnal reptile tetrachromat: 4 cones incl. UV with oil droplets, fovea(s); turtles' red droplets extend red sensitivity.
Measured in this species: colour, night vision and motion (flicker fusion). Measured core: measured values on at least 3 of the 6 dials. Every value below carries its evidence level and sources; nothing is typed by hand.


What stands out
- It has 4 colour receptor classes, including ultraviolet; people have 3.
- It stops seeing flicker at 52.6 Hz, against 60 Hz for people in this dataset, so fast motion looks choppier to it.[9][10]
- Activity pattern: diurnal.
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.
| Dial | Value | Evidence | Sources |
|---|---|---|---|
| Colour | Colour receptors 4 receptor classes: 360 nm (UVS), 450 nm (SWS (blue)), 518 nm (MWS (green)), 618.5 nm (LWS (long)) measured in this species | Measured | [1][2] |
| Ultraviolet yes: at least one receptor peaks in the ultraviolet | Measured | ||
| Sharpness | No value in the catalogue. | ||
| Field of view | No value in the catalogue. | ||
| Sharp zones (foveas) | Number of foveas 2 group default: mode of tier-A values in vision type V14 within phylum Chordata (1 species: Anolis carolinensis) | Group default | [3][4] |
| Fovea type central fovea, temporal | Group default | [3][4] | |
| Night vision | Activity pattern diurnal mode of 4 rows (of 4 rows): diurnal | Measured (not re-verified) | [5][1][6][7] |
| Pupil shape round (or oval) | Measured | [6] | |
| Rods vs cones cone-dominated nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated | Derived | [5][1][6][7] | |
| Motion (flicker fusion) | Flicker fusion frequency 52.6 Hz median of 1 rows (no bright-light flag) (behavioural/whole-eye ERG rows; all rows: [52.6]) | Measured | [8] |
Related animals
- Green anole same vision type
- Anole lizards (Anolis cristatellus) same vision type
- Anole lizards (Anolis grahami) same vision type
- Anole lizards (Anolis gundlachi) same vision type
- Anole lizards (Anolis lineatopus) same vision type
- Anole lizards (Anolis pulchellus) same vision type
More reptiles: all reptiles with measured vision data.
Sources
- Longcore T. 2023. A compendium of photopigment peak sensitivities and visual spectral response curves of terrestrial wildlife to guide design of outdoor nighttime lighting. Basic Appl Ecol 73:40-50. doi:10.1016/j.baae.2023.09.002. doi.org/10.5281/zenodo.8432720
- Thermal Activation and Photoactivation of Visual Pigments (2004)
- Rasys AM, Wegerski A, Trainor PA, Hufnagel RB, Menke DB, Lauderdale JD. 2024. Dynamic changes in ocular shape during human development and its implications for retina fovea formation. BioEssays : news and reviews in molecular, cellular and developmental biology 46(1):e2300054. doi.org/10.1002/bies.202300054
- species_v1:Fleishman et al. 1988 / Makaretz & Levine 1980
- Anderson SR, Wiens JJ. 2017. Out of the dark: 350 million years of conservatism and evolution in diel activity patterns in vertebrates. Evolution 71:1944-1959. Dryad doi:10.5061/dryad.fg700. doi.org/10.5061/dryad.fg700
- Oskyrko O, Mi C, Meiri S, Du W. 2024. ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data 11 (doi:10.1038/s41597-024-03079-5). Dataset v1-2 (includes Meiri 2018 lizard traits). doi.org/10.6084/m9.figshare.24572683.v4
- Moura et al. 2024. A phylogeny-informed characterisation of global tetrapod traits addresses data gaps and biases. PLoS Biol 22:e3002658. TetrapodTraits v3.0.1.. doi.org/10.5281/zenodo.22536349
- Haarlem CS, Hynes C, Jackson AL, Mitchell KJ, O'Connell RG, Healy K. 2026. Pace of ecology drives the tempo of visual perception across the animal kingdom. Nature Ecology & Evolution (doi:10.1038/s41559-026-02994-7). Figshare dataset 10.6084/m9.figshare.30556475. doi.org/10.6084/m9.figshare.30556475
- Healy K, McNally L, Ruxton GD, Cooper N, Jackson AL. 2013. Metabolic rate and body size are linked with perception of temporal information. Animal Behaviour 86:685-696. Table 1. doi.org/10.1016/j.anbehav.2013.06.018
- Inger R, Bennie J, Davies TW, Gaston KJ. 2014. Potential biological and ecological effects of flickering artificial light. PLoS ONE 9(5): e98631. Table 3. doi.org/10.1371/journal.pone.0098631
Every value cites its sources (all sources). Data: catalogue-v1, built 2026-09-29. Accuracy notes: how accurate is this?