Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-27T23:02:25.408Z Has data issue: false hasContentIssue false

The eye of the domesticated sheep with implications for vision

Published online by Cambridge University Press:  02 September 2010

D. Piggins
Affiliation:
Department of Psychology
C. J. C. Phillips
Affiliation:
School of Agricultural and Forest Sciences, University of Wales, Bangor, Gwynedd, North Wales
Get access

Abstract

The eyes of eighteen female sheep (Ovis aries) were refracted and details of inter ocular distance, pupil size, shape and fundus presence recorded. The sheep eyes generally possessed very low hyperopia with little astigmatism, such physiological optics being expected to produce a well focused retinal image for objects in the middle and long distance. No evidence was found for accommodation, which would have produced a well focused ocular image for near objects. A further 10 sheep had their monocular and binocular visual fields measured. The estimated visual field suggests the existence of at least binocular vision, if not the presence of stereopsis. Given the lack of accommodation and a wide inter-ocular distance, it is likely that some degree of stereopsis exists in the animal's middle and long distance vision, but is absent in near vision. These findings support those taken from the animal's neurophysiology and observations of its visually guided behaviour.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Alexander, G. and Shillito, E. E. 1977. The importance of odour, appearance and voice in maternal recognition of the young in Merino sheep (Ovis aries). Applied Animal Ethology 3: 127135.CrossRefGoogle Scholar
Arnold, G. W. 1966. The special senses in grazing animals.1. Sight anddietary habits in sheep. Australian journal of Agricultural Research 17: 521529.CrossRefGoogle Scholar
Backhaus, D. 1959. Visual acuity in ungulates. Zeitschrift fur Tierpsychologie 16: 454.Google Scholar
Baldwin, B. A. 1979. Operant studies on shape discrimination in goats. Physiology and Behaviour 23: 455459.CrossRefGoogle ScholarPubMed
Baldwin, B. A. 1981. Shape discriminationin sheep and calves. Animal Behaviour 29: 830834.CrossRefGoogle Scholar
Barthram, G. T. 1981. Sward structure and the depth of the grazed horizon. Grass and Forage Science 36: 130131 (abstr.).Google Scholar
Bazely, D. R. 1990. Rules and cues used by sheep foraging in monocultures.In Behavioural mechanisms of food selection (ed. Hughes, R. N.), pp. 343366. NATO ASI Series vol. G20. Springer-Verlag, Berlin, Heidelberg.CrossRefGoogle Scholar
Bazley, D.R.Ensor, C.V. 1989. Discrimination learning in sheep with cues varying in brightness hue. Applied Animal Behaviour Science 23: 293299.CrossRefGoogle Scholar
Carroll, L. 1871. Through the looking glass, what Alice found there. Macmillan, London.Google Scholar
Clarke, P. G. H., Donaldson, I. M. L.Whitteridge, D. 1976. Binocular visual mechanisms in cortical areas I II of the sheep. journal of Physiology (London) 256: 509526.CrossRefGoogle Scholar
Clarke, P. G. H.Whitteridge, D. 1976. The cortical visual areas of the sheep. Journal of Physiology (London) 256: 497508.CrossRefGoogle ScholarPubMed
Coile, D. C. and O'Keefe, L. P. 1988. Schematic eyes for domestic animals.Ophthalmic Physiological Optics 8: 215220.CrossRefGoogle ScholarPubMed
Entsu, S., Dohi, H.Yamada, A. 1992. Visual acuity of cattle determined by the method of discrimination learning. Applied Animal Behaviour Science 34: 110.CrossRefGoogle Scholar
Evans, C. R.Piggins, D. J. 1963. A comparison of the behaviour of geometrical shapes when viewed under conditions of steady fixation, and with apparatus for producing a stabilised retinal image. British journal of Physiological Optics 20: 261274.Google ScholarPubMed
Geist, V. 1971. Mountain sheep:a study in behaviour and evolution. University of Chicago Press, Chicago.Google Scholar
Glickstein, M.Millodot, M. 1970. Retinoscopy eye size. Science 168: 605606.CrossRefGoogle ScholarPubMed
Hughes, A. 1977. The topography of vision in mammals of contrasting life style: comparative optics retinal organisation. In Handbook of sensory physiology, vol. VII, 5. The visual system in vertebrates (ed. Crescitelli, F.). Springer-Verlag, Berlin.Google Scholar
Hughes, A.Whitteridge, D. 1973. The receptive fields to pographical organisation of goat retinal ganglion cells. Vision Research 13: 11011114.CrossRefGoogle ScholarPubMed
Kendrick, K. 1990. Through a sheep's eye. New Scientist 12May (no. 1716): 6265.Google Scholar
Kendrick, K. M. 1994. Neurobiological correlates of visual olfactory recognition in sheep. Behavioural Processes 33: 89111.CrossRefGoogle ScholarPubMed
Kendrick, K. M.Baldwin, B. A. 1986. The activity of neurones in the lateral hypothalamus zona incerta of the sheep responding to the sight or approach of food is modified by learning satiety reflects food preference. Brain Research 375: 320328.CrossRefGoogle ScholarPubMed
Kendrick, K. M.Baldwin, B. A. 1987. Cells in temporal cortex of conscious sheep can respond preferentially to the sight of faces. Science 236: 448450.CrossRefGoogle Scholar
Kendrick, K. M.Baldwin, B. A. 1989. The effects o: sodium appetite on the responses of cells in the zona incerte to the sight or ingestion of food, salt water in sheep Brain Research 429: 211218.CrossRefGoogle Scholar
Knowles, A.Dartnell, H. J. A. 1977. Habitat, habit and visual pigments. In The eye, vol. 2B, The photobiology ofvision (ed. Davson, H.), pp. 581648. Academic Press, New York.Google Scholar
Lythgoe, J. N. 1979. The ecology of vision. Clarendon Press Oxford.Google Scholar
Muntz, W. R. A. 1974. Comparative aspects in behavioural studies of vertebrate vision. In The eye, vol. 6, Comparative physiology (ed. Davson, H. and Graham, L. T.), pp. 155226Academic Press, New York.Google Scholar
Newton, I. 1680 in Brewster, D. 1860. Memoirs of the life, writings discoveries of Sir Isaac Newton. Edmonton Douglas, Edinburgh.Google Scholar
Phillips, C. J. C. and Weiguo, L. 1991. Brightness discrimination abilitiesof calves relative to those of humans. Applied Animal Behaviour Science 31: 2533.CrossRefGoogle Scholar
Piggins, D. 1992. Visual perception. In Farm animals the environment (ed. Phillips, C.J.C. and Piggins, D.), pp 131158. CAB International, Wallingford.Google Scholar
Piggins, D., Muntz, W. R. A.Best, R. C. 1983. The eye of the Amazonian manatee, Trichechus inunguis: oculai refraction gross ocular anatomy, retinal histology photopigment. Marine Behavioural Physiology 9: 111130.CrossRefGoogle Scholar
Piggins, D.Phillips, C. J. C. 1996. Sheep vision in “Through the looking glass what Alice found there”. jabberwocky. In press.Google Scholar
Primrose, J. 1964. The functional anomalies of the eye. In Modern ophthalmology. Volume 3.Topical aspects (ed. Sorsby, A.), pp. 3742. Butterworths, London.Google Scholar
Sorsby, A., Benjamin, B., Davey, J. B., Sheridon, M.Tanner, J. M. 1957. Emmetropia its aberrations. Special Report Series No. 293. Medical Research Council, UK.Google Scholar
Van Soest, P. J. 1982. Nutritional ecology of the ruminant. O B Books Inc., Oregon.Google Scholar
Walk, R. D. and Gibson, E. J. 1961. A comparative and analytic study of visual depth perception. Psychological Monographs 75: 144.CrossRefGoogle Scholar
Walls, G. L. 1942. The vertebrate eye its adaptive radiation. Hafner Publishing Company, New York.Google Scholar