When light enters the eye and reaches the retina, several processes occur:
Absorption: Light is absorbed by the photoreceptor cells in the retina called rods and cones. Rods are responsible for vision in low light conditions, while cones are responsible for color vision and visual acuity.
Phototransduction: Once light is absorbed by the rods and cones, a series of chemical reactions called phototransduction take place. These reactions convert the absorbed light energy into electrical signals that can be processed by the brain.
Signal transmission: The electrical signals generated by the phototransduction process are transmitted through a network of neurons in the retina. These signals are modified and amplified as they pass through the retinal circuitry, which helps in enhancing contrast, detecting motion, and extracting features from the visual scene.
Optic nerve transmission: The processed electrical signals, now in the form of neural impulses, are transmitted from the retina to the brain via the optic nerve. The optic nerve carries the visual information to the visual cortex, the region of the brain responsible for processing visual stimuli.
Visual perception: In the visual cortex, the neural impulses are further processed and integrated to form a visual perception. This is where the brain interprets the electrical signals as meaningful visual information, allowing us to perceive and make sense of the visual world around us.
In summary, after light is absorbed by the eyes, it undergoes a complex process of conversion into electrical signals, transmission through the optic nerve, and interpretation by the brain, ultimately leading to visual perception.