Szemek

Szemek are paired sensory organs that detect light and enable sight. They are part of the visual system and work with neural pathways to produce visual perception. In humans, two eyes provide overlapping fields of view, allowing binocular vision and depth perception.

Anatomy: The eye has three layers—the sclera, choroid, and retina. The front segment contains the cornea, iris, pupil, and lens. The cornea and lens focus light onto the retina. The iris adjusts the size of the pupil to regulate the amount of light entering the eye. The retina houses photoreceptor cells: rods for low light and peripheral vision, and cones for color and detail. Signals from photoreceptors travel via the optic nerve to the brain. Extraocular muscles move the eye to track objects and stabilize gaze.

Function: Light is projected through the cornea, lens, and vitreous body onto the retina, where photoreceptors convert it into electrical signals. These signals are transmitted to the brain’s visual cortex, where information from both eyes is integrated to form a single image, supporting depth perception, motion detection, and color vision. The brain processes visual input to interpret shape, distance, and environmental cues.

Health and variation: Vision can be affected by refractive errors such as myopia, hyperopia, and astigmatism. Age-related conditions include cataracts, glaucoma, and macular degeneration. Eye health is supported by regular eye exams, protection from ultraviolet light, proper hygiene, and management of systemic conditions such as diabetes.