Presentation on Lenses
Subject: Physics | Topics:

Lenses are made of transparent materials, like glass or plastic, that typically have an index of refraction greater than that of air. Each of a lens’ two faces is part of a sphere and can be convex or concave (or one face may be flat). If a lens is thicker at the center than the edges, it is a convex, or converging, lens since parallel rays will be converged to meet at the focus. A lens which is thinner in the center than the edges is a concave, or diverging, lens since rays going through it will be spread out.

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