Bending light with lenses is the basis for eyeglasses, binoculars, refracting telescopes and microscopes. Combinations of lenses can be used to make things look bigger, as in a microscope or to make things look closer, as in a telescope. The microscope Microscopes have become very important instruments, especially in the fields of biology and medicine. Modern microscopes use several convex lenses to make nearby objects appear larger. These objective lenses and eyepieces are made with several lens elements, each with different densities to control the sharpness and colour to give the best possible image.
Some optical microscopes can magnify objects hundreds of times.
Back to menu The telescope Reflecting telescopes have become very important in the exploration of space. Telescopes use both mirrors and lenses to produce close-up images of distant objects such as stars and planets. In reflecting telescopes, the first or primary mirror is concave and is the largest mirror. The larger it can be, the better, because as the size goes up, the amount of light collected goes up. The primary mirror reflects the incoming light to a focal point.