concave lens
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Definition
- Noun:
- A lens that causes a parallel beam of light to diverge or spread out: A concave lens is a transparent optical device, thinner at its center than at its edges, which causes incoming parallel rays of light to bend outward, making them appear to originate from a single point.
Usage
- A concave lens is used to correct certain vision problems, like nearsightedness (myopia).
- It is the opposite of a converging (convex) lens.
- It is often described as a .
Examples
- Noun:
- A concave lens is used in the eyeglasses of a nearsighted person.
- The flashlight used a concave lens to widen its beam.
- In the diagram, the concave lens caused the light rays to spread apart.
Advanced Usage
- "To act as a concave lens": Used metaphorically to describe something that spreads out or diffuses focus, attention, or energy.
- The new policy acted like a concave lens, dispersing the team's efforts instead of concentrating them.
Variants and Related Words
- Diverging lens: A direct synonym for a concave lens, emphasizing its function.
- Concave mirror: A related optical device with a reflective surface, but it converges light, unlike a concave lens which diverges it.
- Meniscus lens: A lens with one concave and one convex surface.
Synonyms
- Diverging lens: A lens that causes light rays to spread out.
- Negative lens: A term used in optics, referring to its negative focal length.
Related Phrases
- "Through a concave lens": Figuratively, to view something in a dispersed, widened, or less focused way.
- He saw the complex issue through a concave lens, considering every peripheral factor.
Related Idioms
- None directly associated with the specific term "concave lens." However, the concept relates to idioms about perspective, such as "to look at something through a different lens."
Noun
- a lens such that a parallel beam of light passing through it is caused to diverge or spread out