the Eye Works: How It Works, Explained Simply

Video Transcript

Seeing begins with light. Everything you look at reflects light toward your eyes. That light first passes through the cornea, the clear dome at the front. The cornea does most of the eye's focusing. It then passes through the pupil, the opening in the coloured iris. The iris adjusts the pupil's size to control how much light gets in. Behind the pupil sits the lens. Small muscles change its shape, fine-tuning the focus for objects near or far. The focused light travels through the clear gel filling the eye and lands on the retina, the light-sensing layer lining the back. The retina is packed with millions of light-sensitive cells. Rods handle dim light and side vision, while cones handle colour and fine detail. These cells turn light into electrical signals, which travel along the optic nerve to the brain. The image landing on the retina is actually upside down. Your brain interprets those signals, combines the view from both eyes, and turns them into the single, upright picture you experience as sight. This video is for general education only. It is not medical advice. Ask your eye doctor what's right for you.