Lenses and mirrors
ScienceDefinition
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
- Converging lens in a magnifying glass focusing sunlight
- Concave mirrors in reflecting telescopes gathering starlight
- 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.
Study This Concept
Practice lenses and mirrors with free review games in these units: