Science
Lenses and mirrors.
Definition
Lenses refract (bend) light as it passes through curved transparent material, while mirrors reflect light off a polished surface. Convex lenses converge light to a focal point and concave lenses diverge it; concave mirrors converge light and convex mirrors diverge it. These principles are used in optical instruments like telescopes, microscopes, and eyeglasses.
Examples
Real-world.
- 1 Converging lens in a magnifying glass focusing sunlight
- 2 Concave mirrors in reflecting telescopes gathering starlight
- 3 Corrective eyeglass lenses for nearsightedness or farsightedness
Key Fact
Thin lens equation: 1/f = 1/dₒ + 1/dᵢ, where f is focal length, dₒ is object distance, and dᵢ is image distance.