1. The Human Eye: The human eye is a remarkable example of a natural lens system. The cornea, a transparent outer layer, acts as the primary lens, bending light rays to focus them onto the retina at the back of the eye. The lens inside the eye is flexible, allowing it to adjust focus for objects at different distances. This intricate system allows us to see the world around us in detail.

2. Water Droplets: A water droplet acts like a convex lens, concentrating light. When sunlight passes through a water droplet, it bends the light rays and focuses them to a point. This is why we see rainbows after a rain shower – the water droplets in the air act as tiny lenses, dispersing sunlight into its different colors. This principle is also used in dewdrop photography, where photographers capture the beautiful refraction of light through water droplets.