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Lenses. OBJECTIVE. CONTRAST WAYS IN WHICH LIGHT RAYS ARE BENT BY CONCAVE AND CONVEX LENSES [COS 5 SAT 10]. LENSES. DEFINITION:. A piece of clear glass or plastic that bends light rays passing through it Part of the eye that can focus light
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OBJECTIVE • CONTRAST WAYS IN WHICH LIGHT RAYS ARE BENT BY CONCAVE AND CONVEX LENSES [COS 5 SAT 10]
LENSES • DEFINITION: • A piece of clear glass or plastic that bends light rays passing through it • Part of the eye that can focus light • The lens is found behind the pupil. It bends light that enters the eye.
LENSES • THERE ARE 2 TYPES OF LENSES: 1. Convex Lenses • Concave Lenses
CONVEX LENS • A convex lens is thicker in the middle than at the edges. • When light passes through a convex lens, the rays bend toward each other. • It makes nearby objects look bigger.
CONVEX LENS • People sometimes need lenses to help them see better. • What are people called who need convex lenses? • Farsighted – these people have trouble seeing up close.
CONVEX LENS • Besides glasses and contacts, can you name other convex lenses? MOVIE PROJECTOR SLIDE PROJECTOR TELESCOPES BINOCULARS
LENSES • THE SECOND TYPE OF LENS IS KNOWN AS A CONCAVE LENS.
CONCAVE LENSES • The lens is thicker around the edges than in the middle • When light rays pass through a concave lens, they bend away from each other. • This makes distant objects seem nearer and smaller. Exp: camera viewfinder
CONCAVE LENSES • Concave lenses help people who are nearsighted. These people have trouble seeing distant objects. • Concave lenses bend light rays outward just enough to make distant obj. seem closer.
CONVEX LENSES Thicker in the middle than at the edges Help farsighted people When light passes through a convex lens, the rays bend toward each other. CONCAVE LENSES Thicker around the edges than in the middle Help nearsighted people When light rays pass through a concave lens, they bend away from each other. CONTRAST LENSES
Advantages of Lenses Lenses allow high magnification when they are used in microscopes or telescopes. They are also used in cameras and powerful spotlights Lenses have opened a whole new world to scientists Lenses can lead you out beyond the Earth, to the farthest reaches of the galaxy
OBJECTIVE • CONTRAST WAYS IN WHICH LIGHT RAYS ARE BENT BY CONCAVE AND CONVEX LENSES
CONVEX LENSES Thicker in the middle than at the edges Help farsighted people When light passes through a convex lens, the rays bend toward each other. CONCAVE LENSES Thicker around the edges than in the middle Help nearsighted people When light rays pass through a concave lens, they bend away from each other. CONTRAST LENSES
LENS WRAP UP QUESTIONS SUGGESTIONS ON MAKING THE PRESENTATION MORE EFFECTIVE