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An optical prism is a transparent optical element with flat, polished surfaces that are designed to refract light. At least one surface must be angled — elements with two parallel surfaces are not prisms. The most familiar type of optical prism is the triangular prism, which has a triangular base and rectangular sides.
Prism correction. Prism lenses (here unusually thick) are used for pre-operative prism adaptation. Eye care professionals use prism correction as a component of some eyeglass prescriptions. A lens which includes some amount of prism correction will displace the viewed image horizontally, vertically, or a combination of both directions.
List of optometric abbreviations. Certain abbreviations are current within the profession of optometry. They are used to denote clinical conditions, examination techniques and findings, and various forms of treatment.
Porro prism. Total internal reflection in Porro prism. A single Porro prism. In optics, a Porro prism, named for its inventor Ignazio Porro, is a type of reflection prism used in optical instruments to alter the orientation of an image .
Prism and Base Prism refers to a displacement of the image through the lens, often used to treat strabismus and other binocular vision disorders. The prism value is measured in prism diopters, and Base refers to the direction of displacement. PL is an abbreviation for plano or plain, meaning no prescription
The major components of the phoropter are the battery of spherical and cylindrical lenses, auxiliary devices such as Maddox rods, filtered lenses, prisms, and the JCC (Jackson cross cylinder) used for astigmatism measurement.
The prism fusion range (PFR) or fusional vergence amplitude is a clinical eye test performed by orthoptists, optometrists, and ophthalmologists to assess motor fusion, specifically the extent to which a patient can maintain binocular single vision in the presence of increasing vergence demands.
Since the Howard-Dolman test described above is cumbersome, stereoacuity is usually measured using a stereogram in which separate panels are shown to each eye by superimposing them in a stereoscope using prisms or goggles with color or polarizing filters or alternating occlusion.
The separation of colours by a prism is an example of normal dispersion. At the surfaces of the prism, Snell's law predicts that light incident at an angle θ to the normal will be refracted at an angle arcsin(sin (θ) / n).
A prism sight or prismatic sight, sometimes also called prism scope or prismatic scope, is a type of telescopic sight which uses a reflective prism for its image-erecting system, instead of the series of relay lenses found in traditional telescopic sights.