While the word "prism" occurs mostly commonly in tandem with descriptions of light reflecting and refracting glass pieces, a prism technically constitutes any three-dimensional shape with two faces of the same size and shape and parallelogram sides. The uses of prisms run a large gamut, though the use of light reflecting and refracting prisms relate almost exclusively to optical concerns. In a general sense, prisms figure in all manner of fields, including architecture.
Prisms in Ophthalmology
Ophthalmology is the science dedicated to the study and treatment of eye diseases. Ophthalmologists have used prisms since the 19th century to diagnose and treat a number of diseases of the eye, including esotropia, exotropia, nystagmus and amblyopia. When diagnosing eye diseases or deficiencies, ophthalmologists use the light reflected and refracted by prisms to exam different parts of the eye for problems. Prisms used to treat disease help redirect light entering the eye to enhance the vision of the patient. Prisms also figure in the construction of corrective vision lenses for individuals suffering from certain diseases of the eye or specific types of vision deficiencies.
Prisms in Optical Instruments
Prisms figure prominently in the construction of a number of optical instruments for their ability to bend and manipulate light. Binoculars often use Porro prisms, a single unit built from two prisms that pushes light back in the direction from which it came while vertically and horizontally inverting it. Other optical instruments that use prisms include telescopes, cameras, microscopes and even submarine periscopes. Telescopes in particular use a number of prisms in a single unit as a means of manipulating light travelling great distances to meet the eye.
Prisms in Architecture
Light manipulating prisms figure in architectural projects only in so far as they appear in optical instruments used during construction and design. Prisms as a shape, however, appear commonly in architecture. Architects in Sweden, for instance, use triangular prisms as a common construction design as the slopes of the shape cause snow to run off rather than accumulate. The first skyscrapers were nothing more than giant rectangular prisms while rectangular, triangular and even hexagonal prisms figure into contemporary architecture projects such as the Petronas Towers in Malaysia.
Prisms in Scientific Experiments
Prisms figure prominently in scientific experiments regarding the nature of light and human perception of light. Scientists use prisms when studying the human eye, connections between the eye and the brain, and the general physics of light movement, speed and qualities. Science teachers use prisms in such experiments to teach children about the properties of light. Isaac Newton, the man who discovered gravity, used a prism and the light of the sun when concluding that white light is comprised of all colours in the visible spectrum.