ommatidium


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Related to ommatidium: Rhabdomere

om·ma·tid·i·um

 (ŏm′ə-tĭd′ē-əm)
n. pl. om·ma·tid·i·a (-ē-ə)
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.
[New Latin, diminutive of Greek omma, ommat-, eye; see okw- in Indo-European roots.]
om′ma·tid′i·al (-ē-əl) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

ommatidium

(ˌɒməˈtɪdɪəm)
n, pl -tidia (-ˈtɪdɪə)
(Zoology) any of the numerous cone-shaped units that make up the compound eyes of some arthropods
[C19: via New Latin from Greek ommatidion, from omma eye]
ˌommaˈtidial adj
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

om•ma•tid•i•um

(ˌɒm əˈtɪd i əm)

n., pl. -tid•i•a (-ˈtɪd i ə)
one of the units that make up the compound eye of insects and other arthropods.
[1880–85; < New Latin < Greek ommat-]
om`ma•tid′i•al, adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.

om·ma·tid·i·um

(ŏm′ə-tĭd′ē-əm)
Plural ommatidia
One of the tiny light-sensitive parts of the compound eye of insects and other arthropods. An ommatidium resembles a single simplified eye. See more at compound eye.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.ommatidium - any of the numerous small cone-shaped eyes that make up the compound eyes of some arthropods
ocellus, simple eye, stemma - an eye having a single lens
compound eye - in insects and some crustaceans: composed of many light-sensitive elements each forming a portion of an image
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
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References in periodicals archive ?
At the very center of each ommatidium are the dendrites of one or more neurons called eccentric cells that are electrically coupled to the retinular cells (Fahrenbach, 1969, 1975).
Opsins and Their Expression Patterns in the Xiphosuran Limulus polyphemus
Printed images were magnified, and optical microscope images were used to obtain measurements of dorso-ventral distance (eye width) and anterior-posterior distance (eye length) of the compound eyes, and the SEM images were used to obtain measurements of individual square ommatidium area per eye using a slide caliper (GB/T1214.1-1214.4, Shanghai Hengsheng Tools Co., Ltd., Shanghai, China).
Morphometry of compound eyes of three Bactrocera (Diptera: Tephritidae) species
Watching carefully, the man's mind is helplessly mesmerized by the instantaneous images playing in each ommatidium: it could be an erupting undersea volcano, might be a falcon's-eye view of a landscape, perhaps just a leaf about to fall.
Wu's the man with the compound eyes and the worlding of environmental literature
Each ommatidium has a cornea to focus the light, a long cone full of photoreceptors, and a single axon (neuron) link to the optic nerve at the end, to connect it to the brain.
High-tech camera acts like a bug's eye
Each small eye, known as an ommatidium, consists of a corneal lens, a crystalline cone, and a light sensitive organ at the base.
Insects' eyes inspire new digital camera with unique imaging capabilities
Each ommatidium has its own cornea, lens, and photoreceptor cells for distinguishing brightness and color.
Teaching science from an Islamic perspective
Most of the fossils are fully articulated (excluding macrophytes) and many preserve soft tissues, and organic patterns and structures rarely found in the fossil record: patterns of colouring, nerviation, gut tracts, and ommatidium of insects, stomach contents and muscles of fishes, skin and integumentary tissues of such as frogs, salamanders, lizards, crocodiles and dinosaurs.
A holistic approach to the palaeoecology of Las Hoyas Konservat-Lagerstatte (La Huerguina Formation, Lower Cretaceous, Iberian Ranges, Spain)/ Una aproximacion holistica a la palaeoecologia del Konservat-Lagerstatte de Las Hoyas (Formacion La Huerguina, Cretacico Inferior, Cordillera Iberica, Espana)
Ant compound eye: size-related ommatidium differences within a single wood ant nest.
Relationship between body size and spatial vision in the praying mantis --an ontogenetic study
Eyes reduced to 1 ommatidium. Lamellae of metapleural lobes low.
Una nueva especie de Carebara Westwood (Hymenoptera: Formicidae) y notas taxonomicas sobre el genero
The insect nervous system is adept at setting up a temporary rule of thumb such as, "Steer a course such that the light rays hit your eye at an angle of 30[degrees]." Since insects have compound eyes, this will amount to favoring a particular ommatidium (individual optical tube radiating out from the center of the compound eye).
What use is religion? Part 2
No apparent borders between each ommatidium or between the compound eye and the head were observed.
Photoresponses of the compound eye of the sandhopper Talitrus saltator (Crustacea, Amphipoda) in the ultraviolet-blue range

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