Lenses Flashcards
What is a Concave (Diverging) lens?
A lens that spreads beams of light out
What is a Convex (Converging) Lens?
A lens that brings a beam of light to a focus (used in the eye)
What type of vision problem do Concave Lens’ fix?
Short Sightedness
What type of vision problem do Convex Lens’ fix?
Long Sightedness
What is Short Sightedness?
In short sight, beams of light from a distant object focus in front of the retina
You can’t focus on distant objects
How do Concave Lens’ correct Short Sightedness?
The concave lens spreads out the light so it focuses on the retina
What is Long Sightedness?
In Long sight, beams of light from a nearby focus behind the retina
You can’t focus on nearby objects
How do Convex Lens’ correct Long Sightedness?
The convex lens focuses the light closer in onto the retina
What are the different types of image that lenses produce and what do they mean?
Magnified (made larger) Upright (same way up as object) Diminished (made smaller) Inverted (upside down) Virtual Real
What are the uses of a Convex lens?
Magnifying Glass Camera Eye Projector Microscope Telescope
What are the uses of a Concave Lens?
Spy Holes
Back windows of Coaches