superposition eye

compound eye

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July 14, 2026

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A compound eye is an eye composed of many individual visual units, often seen in insects. These eyes are convex structures where light enters through multiple lenses, giving them a faceted appearance. Each unit, called an ommatidium, contains several retinal cells surrounding a light-sensitive area called the rhabdom.123

Superposition eyes are a type of compound eye found in nocturnal or crepuscular insects and crustaceans. Unlike apposition eyes, superposition eyes form a single, erect image by combining light rays from numerous facets. This results in a brighter, though less sharp, image compared to apposition eyes. These eyes can utilize refracting, reflecting, or a combination of optical mechanisms to achieve image formation.34

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photoreception
Superposition eyes
Crepuscular (active at twilight) and nocturnal insects (e.g., moths), as well as many crustaceans from the dim midwater regions of the ocean, have compound eyes known as superposition eyes, which are fundamentally different from the apposition type. Superposition eyes look superficially similar to…
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Crepuscular (active at twilight) and nocturnal insects (e.g., moths), as well as many crustaceans from the dim midwater regions of the ocean, have compound eyes known as superposition eyes, which are fundamentally different from the apposition type. Superposition eyes look superficially similar to…
Read More

insect
Eyes
This is called a superposition eye. The image formed is brighter but not as sharp as that formed by the apposition eye. In addition to perceiving brightness, the eyes of insects can perceive colour as well as some other properties of light.
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This is called a superposition eye. The image formed is brighter but not as sharp as that formed by the apposition eye. In addition to perceiving brightness, the eyes of insects can perceive colour as well as some other properties of light.
Read More