Results 151 to 160 of about 785 (184)
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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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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, 1976Fresnel 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
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Fresnel membrane prisms: clinical experience.
Canadian journal of ophthalmology. Journal canadien d'ophtalmologie, 2000There 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, 1997Abstract 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 +6 more
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The effectivity of Fresnel prisms for visual field enhancement.
Journal of the American Optometric Association, 1993An 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, 1974The 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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[Fresnel prisms--their value in the rehabilitation of homonymous hemianopsias].
Klinische Monatsblatter fur Augenheilkunde, 1988The use of press-on Fresnel prisms is described as a simple inexpensive technique to rehabilitate patients with homonymous hemianopsia. The optical principle of prismatic displacement from the blind to the seeing fields is detailed herein. Forty-one patients were evaluated over a 10 year period. Twenty per cent benefited from the prism.
T R, Hedges, J, Stunkard, A, Twer
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Fresnel prisms and their effects on visual acuity and binocularity.
Transactions of the American Ophthalmological Society, 19791. The visual acuity with the Fresnel membrane prism is significantly less than that with the conventional prism of the same power for all prism powers from 12 delta through 30 delata at distance and from 15 delta through 30 delta at near. 2. The difference in the visual acuity between base up and base down, and between base in and base out, is not ...
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