Definitions
from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun One of the optical units, consisting of photoreceptors and usually one or more lenses, that make up a compound eye of an insect or a crustacean.
from The Century Dictionary.
- noun A radial element or segment of the compound eye of an arthropod.
from the GNU version of the Collaborative International Dictionary of English.
- noun (Zoöl.) One of the single eyes forming the compound eyes of crustaceans, insects, and other invertebrates; one of the eyes of an ommateum.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun zoology One of the conical substructures which make up the
eyes ofinvertebrates .
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun any of the numerous small cone-shaped eyes that make up the compound eyes of some arthropods
Etymologies
from The American Heritage® Dictionary of the English Language, 4th Edition
from Wiktionary, Creative Commons Attribution/Share-Alike License
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Examples
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Since insects have compound eyes (with straight tubes or light guides radiating out from the centre of the eye like the spines of a hedgehog), this might amount in practice to something as simple as keeping the light in one particular tube or ommatidium.
The God Delusion Dawkins, Richard, 1941- 2006
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We do not know the stages through which the eye has passed to its present perfected state, but, since the number of simple eyes (facets) has become very much greater in the male than in the female, we may assume that their increase is due to a gradual duplication of the determinants of the ommatidium in the germ-plasm, as I have already indicated in regard to sense-organs in general.
Evolution in Modern Thought Gustav Schwalbe 1880
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In Bombus impatiens a similar pattern is likely, since UV opsin is found in zero, one or two receptors per ommatidium, and these cells always correspond to the R1 or R5 photoreceptors
PLoS ONE Alerts: New Articles Peter Skorupski et al. 2010
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In the honeybee each ommatidium contains six green photoreceptors, which give rise to the short visual fibres.
PLoS ONE Alerts: New Articles Peter Skorupski et al. 2010
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Each of the crab's ommatidium is like one of your camera's pixels - but instead of millions there is just 8,000.
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Each of the crab's ommatidium is like one of your camera's pixels - but instead of millions there is just 8,000.
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Each of the crab's ommatidium is like one of your camera's pixels - but instead of millions there is just 8,000.
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Their compound eyes have up to 30,000 facets, each of which is a separate light-sensing organ or ommatidium, arranged to give nearly a 360° field of vision, important for taking prey on the wing, as has done the female shown above.
Michigan in Pictures 2009
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Nephrops norvegicus), and increases in sensitivity up to 1000 above the more common apposition type eye (where light remains within a single facet/ommatidium).
CreationWiki - Recent changes [en] Ashcraft 2010
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