øyne

Øyne are the organs of sight, responsible for detecting light and translating it into images that the brain can interpret. Found in most vertebrates and many invertebrates, the basic structure of an eye involves a lens that focuses light onto a light-sensitive layer, typically the retina. The retina contains photoreceptor cells, rods and cones, which convert light into electrical signals. These signals are then transmitted to the brain via the optic nerve.

The complexity of eyes varies greatly across the animal kingdom. Simple eyespots can detect light intensity and direction, while compound eyes, common in insects, consist of numerous individual units called ommatidia, each with its own lens and photoreceptors, allowing for a wide field of vision and excellent motion detection. Camera-type eyes, similar to those of humans, possess a single lens and a more sophisticated retina, enabling the perception of detailed images and color.

The iris, a muscular diaphragm, controls the size of the pupil, regulating the amount of light entering the eye. The cornea, the transparent outer layer, also plays a role in focusing light. The fluid-filled chambers within the eye help maintain its shape and provide nourishment. The precise functioning of the eye is a remarkable biological feat, essential for survival, navigation, and interaction with the environment.