värinäössä

Värinäkö, also known as color vision, refers to the ability of an organism to distinguish objects based on the wavelengths of light they reflect, absorb, or emit. In humans, this perception is primarily mediated by specialized photoreceptor cells in the retina called cones. There are typically three types of cones, each sensitive to different ranges of wavelengths, corresponding roughly to red, green, and blue light. The brain then interprets the combined signals from these cones to create the sensation of color.

The spectrum of visible light is continuous, but humans generally perceive a range of colors from violet through red. The way an individual perceives color can vary. Color blindness, or color vision deficiency, is a condition where a person has difficulty distinguishing certain colors. This is often due to a deficiency or absence of one or more types of cone cells, or a problem with the neural pathways that process color information. The most common forms of color blindness involve difficulty distinguishing between red and green hues.

Beyond humans, color vision varies greatly across the animal kingdom. Many animals have different numbers and types of cone cells, leading to different color perception capabilities. For example, some birds and insects can see ultraviolet light, which is invisible to humans. The evolution of color vision is thought to be linked to factors such as finding food, identifying mates, and avoiding predators. The study of color vision involves understanding the physics of light, the biology of the eye and brain, and the psychology of perception.