Compound eye

A compound eye is a special kind of visual organ found in many arthropods, including insects and crustaceans. These eyes are made up of thousands of tiny parts called ommatidia. Each ommatidium has its own cornea, lens, and photoreceptor cells that can sense brightness and color.

The way a compound eye sees is quite different from human eyes. Instead of one main lens focusing light, each ommatidium points in a slightly different direction. The brain combines all these tiny images to form a complete picture. While this gives a less sharp image than our single-lens eyes, it allows the arthropod to see a much wider area and notice fast movements quickly.

One amazing feature of compound eyes is their ability to detect changes in light quickly. This helps animals like honey bees react to movement much faster than humans. Their eyes can notice flickers of light and movement in just a fraction of a second, helping them stay alert and safe in their busy lives.

Types

Compound eyes are special eyes found in insects and other small animals. They can be of two main types: apposition eyes and superposition eyes.

Apposition eyes have a lens that focuses light from one direction, while other light is blocked. Some animals, like the mantis shrimp, have this type of eye. Another kind of apposition eye is found in Strepsiptera, where each lens creates an image that the brain combines.

Superposition eyes come in three types. The refracting type has a space between the lens and the light sensor, and it is often used by night-active insects. The parabolic type, found in mayflies, uses curved surfaces to focus light. Some shrimp, prawns, crayfish, and lobsters have reflecting superposition eyes that use mirrors instead of lenses.

Cultural references

People have been inspired by the many-eyed look of insects for thousands of years. Long ago, glass beads called “dragonfly eyes” were made in both Western and Eastern Asia. Because of how they look and work, compound eyes have appeared in art, movies, and books, especially since 2010.

Some examples include:

• The Man with the Compound Eyes, a novel from 2011 by Wu Ming-yi
• Dragonfly Eyes, a movie from 2017 by Xu Bing
• Dragonfly Eyes, a novel from 2016 by Cao Wenxuan