Search results
Results from the WOW.Com Content Network
A Nicol prism is a type of polarizer. It is an optical device made from calcite crystal used to convert ordinary light into plane polarized light. It is made in such a way that it eliminates one of the rays by total internal reflection, i.e. the ordinary ray is eliminated and only the extraordinary ray is transmitted through the prism .
Typically, the patient sits behind the phoropter, and looks through it at an eye chart placed at optical infinity (20 feet or 6 metres), then at near (16 inches or 40 centimetres) for individuals needing reading glasses. The eye care professional then changes lenses and other settings, while asking the patient for subjective feedback on which settings gave the best vision. The patient's ...
The vertical bar, |, is a glyph with various uses in mathematics, computing, and typography. It has many names, often related to particular meanings: Sheffer stroke (in logic ), pipe, bar, or (literally the word "or"), vbar, and others.
EnChroma lenses are designed, manufactured, marketed and distributed by EnChroma, inc. in Berkeley, California. EnChroma glasses were invented incidentally in 2002 by Donald McPherson while trying to develop lenses to protect and aid surgeons during laser operations. The company received a grant from the NIH in 2005 and the glasses were released to the public in 2012, with cheaper versions ...
The circumzenithal arc, also called the circumzenith arc ( CZA ), the upside-down rainbow, and the Bravais arc, [1] is an optical phenomenon similar in appearance to a rainbow, but belonging to the family of halos arising from refraction of sunlight through ice crystals, generally in cirrus or cirrostratus clouds, rather than from raindrops.
Conversely, a direction or plane is said to be horizontal (or leveled) if it is perpendicular to the vertical direction. In general, something that is vertical can be drawn from up to down (or down to up), such as the y-axis in the Cartesian coordinate system .
Ad
related to: vertical prism in glasses