ommatidium
noun
om·ma·tid·i·um
ˌä-mə-ˈti-dē-əm 
plural ommatidia
ˌä-mə-ˈti-dē-ə
: one of the elements corresponding to a small simple eye that make up the compound eye of an arthropod
Examples of ommatidium in a Sentence
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At the top of each ommatidium is a lens, with cone cells beneath it that also help focus incoming light.
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Scott K. Johnson, Ars Technica, 15 Aug. 2020
The tiny organ contains 100 ommatidia, or subunits that make up compound eyes found today in many insects, surrounding a light-sensing structure called a rhabdom.
—Jason Daley, Smithsonian, 11 Dec. 2017
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Scott K. Johnson, Ars Technica, 15 Aug. 2020
The tiny organ contains 100 ommatidia, or subunits that make up compound eyes found today in many insects, surrounding a light-sensing structure called a rhabdom.
—Jason Daley, Smithsonian, 11 Dec. 2017
Cite this Entry
“Ommatidium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ommatidium. Accessed 3 Nov. 2025.
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