Analyze Diet
Vision research1992; 32(12); 2289-2293; doi: 10.1016/0042-6989(92)90092-w

Visual acuity in the horse.

Abstract: We assessed the ease with which horses could learn visual discriminations and measured their resolution acuity. We trained three horses to press their noses against one of two large wooden panels to receive a small food reward. Following training on a series of two-choice discrimination tasks, resolution acuity was measured. Although there was some variability between animals, the best acuity obtained was 23.3 c deg-1. Within the margin of error imposed by limited anatomical data, the obtained values are consistent with predictions based on retinal ganglion cell density estimates and posterior nodal distance/axial length ratios. They suggest that the resolution acuity of the horse is limited by ganglion cell density in the temporal portion of the narrow visual streak.
Publication Date: 1992-12-01 PubMed ID: 1288005DOI: 10.1016/0042-6989(92)90092-wGoogle Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
  • Journal Article
  • Research Support
  • Non-U.S. Gov't

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This study explores and measures the visual acuity of horses, primarily their ability to recognize details. The findings reveal that the resolution acuity of horses is likely limited by the density of ganglion cells in a specific part of the horse’s visual field.

Experiment Design

  • The researchers trained three horses to distinguish between two large wooden panels by pressing their noses against one of them in exchange for a small food reward. This created a setup in which horses had to rely on their vision to perform specific tasks, thereby allowing their visual abilities to be measured.
  • This experiment involved a series of two-choice discrimination tasks that were performed following the initial training. These tasks were used to measure the resolution acuity, or the ability to recognize minute details, of the horses.

Results and Observations

  • There was some variability observed in the results obtained from the individual animals, meaning that not all horses demonstrated the same level of visual acuity during this study.
  • The highest visual acuity recorded in this experiment was 23.3 cycles per degree, a measurement that describes the finest visual detail that an individual can perceive.
  • The results obtained match predictions made based on the retinal ganglion cell density and posterior nodal distance or axial length ratios.

Conclusions

  • The findings from this study suggest that the ganglion cell density in the temporal portion of the narrow visual streak determines the resolution acuity of the horse.
  • In simpler terms, the density of certain cells in part of the horse’s eye may limit the level of detail the horse can see.
  • The experiment’s results provided important insights into how vision works in horses and contributes to knowledge on mammalian vision more broadly.

Cite This Article

APA
Timney B, Keil K. (1992). Visual acuity in the horse. Vision Res, 32(12), 2289-2293. https://doi.org/10.1016/0042-6989(92)90092-w

Publication

ISSN: 0042-6989
NlmUniqueID: 0417402
Country: England
Language: English
Volume: 32
Issue: 12
Pages: 2289-2293

Researcher Affiliations

Timney, B
  • Department of Psychology, University of Western Ontario, London, Canada.
Keil, K

    MeSH Terms

    • Animals
    • Discrimination, Psychological / physiology
    • Female
    • Horses / physiology
    • Pattern Recognition, Visual / physiology
    • Retinal Ganglion Cells / physiology
    • Sensory Thresholds / physiology
    • Visual Acuity / physiology

    Citations

    This article has been cited 13 times.
    1. Schubert CL, Ryckewaert B, Pereira C, Matsuzawa T. Garrano Horses Perceive Letters of the Alphabet on a Touchscreen System: A Pilot Study.. Animals (Basel) 2022 Dec 12;12(24).
      doi: 10.3390/ani12243514pubmed: 36552434google scholar: lookup
    2. Graïc JM, Peruffo A, Corain L, Finos L, Grisan E, Cozzi B. The primary visual cortex of Cetartiodactyls: organization, cytoarchitectonics and comparison with perissodactyls and primates.. Brain Struct Funct 2022 May;227(4):1195-1225.
      doi: 10.1007/s00429-021-02392-8pubmed: 34604923google scholar: lookup
    3. Ragonese G, Baragli P, Mariti C, Gazzano A, Lanatà A, Ferlazzo A, Fazio E, Cravana C. Interspecific two-dimensional visual discrimination of faces in horses (Equus caballus).. PLoS One 2021;16(2):e0247310.
      doi: 10.1371/journal.pone.0247310pubmed: 33606816google scholar: lookup
    4. Cappellato A, Miletto Petrazzini ME, Bisazza A, Dadda M, Agrillo C. Susceptibility to Size Visual Illusions in a Non-Primate Mammal (Equus caballus).. Animals (Basel) 2020 Sep 17;10(9).
      doi: 10.3390/ani10091673pubmed: 32957449google scholar: lookup
    5. Lansade L, Colson V, Parias C, Trösch M, Reigner F, Calandreau L. Female horses spontaneously identify a photograph of their keeper, last seen six months previously.. Sci Rep 2020 Apr 14;10(1):6302.
      doi: 10.1038/s41598-020-62940-wpubmed: 32286345google scholar: lookup
    6. Paul SC, Stevens M. Horse vision and obstacle visibility in horseracing.. Appl Anim Behav Sci 2020 Jan;222:104882.
    7. Feng LC, Chouinard PA, Howell TJ, Bennett PC. Why do animals differ in their susceptibility to geometrical illusions?. Psychon Bull Rev 2017 Apr;24(2):262-276.
      doi: 10.3758/s13423-016-1133-3pubmed: 27488557google scholar: lookup
    8. Tomonaga M, Kumazaki K, Camus F, Nicod S, Pereira C, Matsuzawa T. A horse's eye view: size and shape discrimination compared with other mammals.. Biol Lett 2015 Nov;11(11).
      doi: 10.1098/rsbl.2015.0701pubmed: 26601679google scholar: lookup
    9. Wathan J, Burrows AM, Waller BM, McComb K. EquiFACS: The Equine Facial Action Coding System.. PLoS One 2015;10(8):e0131738.
      doi: 10.1371/journal.pone.0131738pubmed: 26244573google scholar: lookup
    10. Yamaue Y, Hosaka YZ, Uehara M. Spatial relationships among the cellular tapetum, visual streak and rod density in dogs.. J Vet Med Sci 2015 Feb;77(2):175-9.
      doi: 10.1292/jvms.14-0447pubmed: 25728250google scholar: lookup
    11. Shinozaki A, Takagi S, Hosaka YZ, Uehara M. The fibrous tapetum of the horse eye.. J Anat 2013 Nov;223(5):509-18.
      doi: 10.1111/joa.12100pubmed: 24102505google scholar: lookup
    12. Henselek Y, Fischer J, Schloegl C. Does the stimulus type influence horses' performance in a quantity discrimination task?. Front Psychol 2012;3:504.
      doi: 10.3389/fpsyg.2012.00504pubmed: 23181043google scholar: lookup
    13. Miyashita Y, Nakajima S, Imada H. Differential outcome effect in the horse.. J Exp Anal Behav 2000 Sep;74(2):245-53.
      doi: 10.1901/jeab.2000.74-245pubmed: 11029025google scholar: lookup