Receptor ➡️ Sensory neuron➡️ Brain ➡️ Motor neuron ➡️ Eye ➡️ Eye muscle contracts.
- Light Enters the Eye: The light first passes through the cornea, the clear dome-shaped structure at the front of the eye that protects it and begins focusing the light.
- Pupil Contracts: The iris, the colored part of the eye, controls the size of the pupil. When exposed to bright light, the iris contracts, making the pupil smaller to reduce the amount of light entering the eye. 🌞
- Lens Adjusts: The lens, located behind the pupil, adjusts its shape to focus light onto the retina. When in bright light, the lens flattens to focus the light more sharply. 📍
- Light Reaches the Retina: The retina is the light-sensitive tissue at the back of the eye, filled with photoreceptor cells that convert light into electrical signals.
- Photoreceptor Cells Respond: There are two types of photoreceptors:
- Rods: More sensitive to light but don’t detect color.
- Cones: Less sensitive to light but responsible for color vision. Under bright light, the cones are more stimulated, giving us clear and colored vision. 🌈
- Electrical Signals Sent to the Brain: The retina sends these electrical signals to the optic nerve, which transmits them to the brain. 🧠
- Brain Processes the Information: The brain processes the information, creating a visual image and adjusting the pupil size and lens curvature to maintain proper vision in changing light conditions.
This process happens almost instantly, allowing us to quickly adapt to different lighting environments.
