Ommatidium (Noun)
Meaning
Any of the numerous small cone-shaped eyes that make up the compound eyes of some arthropods.
Classification
Nouns denoting body parts.
Examples
- The ommatidium is the basic unit of the compound eye of insects and arachnids, and is equipped with its own lens, cornea, and photoreceptor cells.
- Each ommatidium provides a small but distinct image of the environment, which is then combined by the insect's nervous system to form a complete picture.
- The dragonfly's ommatidium is nearly square in cross-section, allowing for extremely wide receptive fields and almost 360-degree vision.
- Flies have a large number of ommatidia in each compound eye, giving them nearly complete spherical vision, although the image quality is quite poor.
- In bees, each ommatidium is surrounded by a UV-reflecting pigment, which helps to guide light into the photoreceptors and enhance UV sensitivity.