nägemusest

Nägemus, also known as vision, is the ability to perceive light and interpret it as images. It is one of the most complex and vital senses for humans and many animals. The process begins when light enters the eye through the cornea, a transparent outer layer, and then the pupil, an opening controlled by the iris. The lens, located behind the iris, focuses this light onto the retina at the back of the eye.

The retina contains specialized cells called photoreceptors: rods and cones. Rods are responsible for vision in low light conditions and detect shades of gray, while cones are active in brighter light and are responsible for color vision and sharp detail. When light strikes these photoreceptors, they convert it into electrical signals.

These electrical signals are then transmitted through the optic nerve to the brain, specifically to the visual cortex in the occipital lobe. Here, the signals are processed and interpreted, creating the perception of sight. This complex interplay of light, ocular structures, and neural pathways allows us to navigate our environment, recognize objects and faces, and experience the world in its visual richness. Impairments in any part of this system can lead to various vision problems, ranging from blurry vision to complete blindness.