How to use an Ophthalmoscope
... For the operator with normal refraction and the instrument held 3-5cm from the horse’s eye, at 0 the optic disc can typically be brought into sharp focus (Fig 3). This will vary with the refraction of the operator’s eye and with the viewing distance selected. The fundic image is upright and magn ...
... For the operator with normal refraction and the instrument held 3-5cm from the horse’s eye, at 0 the optic disc can typically be brought into sharp focus (Fig 3). This will vary with the refraction of the operator’s eye and with the viewing distance selected. The fundic image is upright and magn ...
Refraction, Lenses, Aberrations
... A lens is a piece of glass (plastic) with two refracting surfaces, which are either curved (e.g., a segment of a sphere) or plain. Lenses are used to form images by refraction in optical instruments (microscopes, telescopes, cameras, etc.) ...
... A lens is a piece of glass (plastic) with two refracting surfaces, which are either curved (e.g., a segment of a sphere) or plain. Lenses are used to form images by refraction in optical instruments (microscopes, telescopes, cameras, etc.) ...
Human Vision: Electrophysiology and Psychophysics
... The refractive index of a transparent substance is the ratio of the velocity of light in air to that in the substance ...
... The refractive index of a transparent substance is the ratio of the velocity of light in air to that in the substance ...
Aspheric Lenses
... The low dispersion glass types are often found in telephoto lenses where fast f/stops are desired. The effects of dispersion are called chromatic aberration. Early solutions for chromatic aberrations included incorporation of radioactive materials into optical glass. ...
... The low dispersion glass types are often found in telephoto lenses where fast f/stops are desired. The effects of dispersion are called chromatic aberration. Early solutions for chromatic aberrations included incorporation of radioactive materials into optical glass. ...
Emerging Trends in Contact Lens Technology Jason Jedlicka, OD
... Trends in Soft Lenses for Irregular Corneas Better materials Should they be in Si Hy only? Better designs Many new designs and more coming What is the difference in all these designs? KC specific vs. Irregular cornea generically Possible higher order aberration technology Trends in Soft Lenses for P ...
... Trends in Soft Lenses for Irregular Corneas Better materials Should they be in Si Hy only? Better designs Many new designs and more coming What is the difference in all these designs? KC specific vs. Irregular cornea generically Possible higher order aberration technology Trends in Soft Lenses for P ...
Microscopy - u.arizona.edu
... A. Eyes and Brain like to compare differences in either color or intensity of light B. Allows better detail to be “seen”; defines edges, borders, etc. e. Aberrations A. Lens are not perfect; chromatic, spherical aberrations occur among others B. The higher the quality of the lens, the less aberratio ...
... A. Eyes and Brain like to compare differences in either color or intensity of light B. Allows better detail to be “seen”; defines edges, borders, etc. e. Aberrations A. Lens are not perfect; chromatic, spherical aberrations occur among others B. The higher the quality of the lens, the less aberratio ...
Schneider Kreuznach
Schneider Kreuznach (German pronunciation: [ˌʃnaɪdɐ ˈkʁɔʏtsnax]) is the abbreviated name of the company Jos. Schneider Optische Werke GmbH, which is sometimes also simply referred to as Schneider. They are a manufacturer of industrial and photographic optics. The company was founded on 18 January 1913 by Joseph Schneider as Optische Anstalt Jos. Schneider & Co. at Bad Kreuznach in Germany. The company changed its name to Jos. Schneider & Co., Optische Werke, Kreuznach in 1922, and to the current Jos. Schneider Optische Werke GmbH in 1998.The company is known partly for its many innovative lens designs over the course of its existence. In 2001, Schneider received an Oscar for Technical Achievement for their Super-Cinelux motion picture lenses. They are best known as manufacturers of high-quality large format lenses for view cameras, enlarger lenses, and high quality photographic loupes. They also make a limited amount of small- and medium-format lenses, and have, at various times, manufactured eyeglasses and camera rangefinders, as well as being an OEM lens maker for Kodak and Samsung digital cameras. They currently supply the lenses for the LG Dare, LG Viewty KU990, LG Renoir KC910, LG Viewty Smart GC900 and the LG enV Touch. They also supplied the lenses for the Kodak Regent camera in the 1930s and the classic Kodak Retina and Kodak Retinette camera series in the 1950s and 1960s. In 1961, they created Feinwerktechnik GmbH, a manufacturer of electrical-hydraulic servo valves. Over the past several years, they have acquired several other companies:In 1985, they acquired the B+W Filter Manufacturing Company (founded in 1947 by partners Biermann and Weber), maker of the well-respected line of B+W filters. In July 1987, they purchased Rollei Fototechnic GmbH.In 1989, they purchased Käsemann/Oberaudorf, a manufacturer of glass and plastic polarizing materials.After 1991 they acquired the former East-German (GDR) camera and lens manufacturer Pentacon/Practica (Dresden)In 2000, they acquired Century Optics, an American lensmaking firm.From the start of its production in 1914, Schneider had produced their 500,000th lens by June 1932, their millionth by November 1936, and their 10 millionth lens by January 1967. As of April 2000, they have produced over 14,730,000 lenses. The list below converts any cm designations on earlier lenses to mm (so a 16.5 cm lens is shown as a 165 mm lens).