Results 151 to 160 of about 173,282 (180)

The Amorphic Fresnel Prism Trioptical System

1987
Severe visual field constriction, characteristic of conditions such as retinitis pigmentosa and end stage glaucoma creates significant limitations on an individual’s mobility and activities of daily living. In such cases, reverse telescopic systems have been utilized in an attempt to expand the visual field [1,2]. These image minification systems focus
Richard L. Brilliant, Sarah D. Appel, Robert J. Ruggiero   +2 more
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A FRESNEL PRISM BAR FOR HOME VISUAL THERAPY

Optometry and Vision Science, 1974
ABSTRACT Fabrication of an inexpensive, easy‐to‐use prism bar using Fresnel Press‐on TM prisms is discussed.
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Hemianopic Fresnel prisms.

Journal of clinical neuro-ophthalmology, 1983
Patients with homonymous hemianopic visual field defects have been treated by using a 30-diopter Fresnel plastic paste-on prism on their glasses. A patient with a left homonymous hemianopia, for instance, can have a 30-diopter base left (i.e., base out) Fresnel prism placed on the temporal half of the left spectacle lens.
J L, Smith, I G, Weiner, A J, Lucero
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FIR Fresnel Prism used as a Quarterwaye Plate

1976 International Conference on Submillimeter Waves and Their Applications, 1976
Fresnel prisms were extensively studied and used in the optical region of the spectrum /1/. When radiation propagates in a medium towards a surface that separates the given medium from an optically less dense material, then total reflection may occur, when the angle of incidence is greater than the critical angle of the optically dense medium.
U. O. Farrukh, G. A. Koepf
openaire   +1 more source

Comparison of the visual effects of Fresnel prisms in normal and amblyopic eyes

Journal of American Association for Pediatric Ophthalmology and Strabismus, 2008
To assess the effects of Fresnel prisms on visual acuity and peak contrast sensitivity in the amblyopic and sound eyes of participants with amblyopia and to determine whether these functions were affected by Fresnel prisms to a different degree than those of controls.The LogMAR visual acuity and peak contrast sensitivity of 10 unilateral amblyopic ...
David, Wright, Alison Y, Firth, David, Buckley   +2 more
openaire   +2 more sources

Visual performance and optical properties of Fresnel membrane prisms.

American journal of optometry and archives of American Academy of Optometry, 1971
The Fresnel prism, an outgrowth of the early nineteenth century lenses designed for light‐houses by Augustin J. Fresnel, can be imagined as a series of small prisms lying adjacent to each other on a thin transparent platform.
A J, Adams, R J, Kapash, E, Barkan
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Fresnel membrane prisms: clinical experience.

Canadian journal of ophthalmology. Journal canadien d'ophtalmologie, 2000
There are few published reports on the clinical application of Fresnel membrane prisms in the treatment of diplopia in adults. The authors describe the use of these prisms in patients with fourth and sixth cranial nerve palsies, restrictive motility caused by thyroid-related orbital disease, and convergence insufficiency.Of 209 patients who had been ...
M, Flanders, N, Sarkis
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A Fresnel bi-prism device for atomic matter waves

Optics Communications, 1997
Abstract The principle of a simple bi-prism for coherent atomic translational waves is studied. The scheme of the experiment consists of a diffracting slit, in front of which the evanescent wave running along a tapered optical fibre provides a converging gradient of optical potential for two-level atoms.
R. Brouri, F. de Tomasi, J. Baudon, J. Reinhardt, V. Lorent, J. Robert, M. Gorlicki   +6 more
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The effectivity of Fresnel prisms for visual field enhancement.

Journal of the American Optometric Association, 1993
An objective method for placement of Fresnel prisms has been used to enhance constricted visual fields at the Eastern Blind Rehabilitation Center in West Haven, CT since 1975. To study the effectiveness of this method, 22 patients fitted with prisms since 1986 participated in a survey regarding their level of satisfaction with the prisms.
E, Hoppe, R R, Perlin
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Polarization Conserving Light Bending Prisms and Optimized Fresnel Rhombs

Applied Optics, 1974
The design of prisms utilizing total internal reflection to achieve particular phase retardation is considered. Two prisms are discussed that bend light by 90 degrees without changing its polarization. Optimum design for Fresnel rhombs is considered, and designs for quarter-wave and half-wave are presented. The effect of light beam divergence and prism
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