What is Vision?
Vision is the ability to interpret the surrounding environment by processing information contained in visible light. It's a complex process involving the eyes and brain, converting light waves into images.
Visible Light Spectrum
The human eye perceives light within a wavelength range of about 380 to 750 nanometers. Beyond this visible spectrum, ultraviolet and infrared light exist, which humans cannot see unaided.
Eye Anatomy Essentials
The eye has several key components: the cornea, pupil, lens, retina, and optic nerve. These parts work together to focus light and translate it into electrical impulses for the brain.
Photoreceptor Dynamics
Rod and cone cells in the retina detect light. Rods are sensitive to low light and motion, while cones discern color and detail. Humans typically have three cone types for red, green, and blue light.
Color Vision Variability
Color perception varies among individuals. Some people may have four types of cones (tetrachromats) and see up to 100 million colors, while others (colorblind) may struggle to differentiate certain hues.
Light and Circadian Rhythms
Exposure to light influences our circadian rhythms, affecting sleep and alertness. Particularly, blue light has a strong impact, which is why screen time before bed can disrupt sleep patterns.
Vision's Evolutionary Wonders
Vision has evolved uniquely across species. For example, mantis shrimp have the most complex eyes in the animal kingdom, with 12 to 16 types of photoreceptor cells for color analysis.
What processes visible light into images?
Brain and heart
Eyes and brain
Ears and skin
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