Results 141 to 150 of about 165,986 (168)

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
openaire   +1 more source

Contrast sensitivity through hybrid diffractive, Fresnel, and refractive prisms

Optometry - Journal of the American Optometric Association, 2004
Fresnel and wedge-shaped refractive prisms are used diagnostically and therapeutically in clinical practice. This article extends the study on the effect of prisms on visual acuity to the effect on contrast sensitivity by membrane Fresnel (F), refractive (R), and newly designed hybrid diffractive (C) prisms (ComPrisms), which combine a wedge-shaped ...
openaire   +2 more sources

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
openaire   +2 more sources

Fresnel Prism Affects the Balance in Hemiplegic Stroke Patients without Neglect

, 2020
Songhee Park, Sun-young Ha, Yun-Hee Sung
semanticscholar   +1 more source

[Fresnel prisms--their value in the rehabilitation of homonymous hemianopsias].

Klinische Monatsblatter fur Augenheilkunde, 1988
The 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
openaire   +1 more source

Safety and efficacy of an intraocular Fresnel prism intraocular lens in patients with advanced macular disease: Initial clinical experience

Journal of cataract and refractive surgery, 2014
Frederik J Potgieter, C. Claoué
semanticscholar   +1 more source

Response to the Letter to the Editor-Fresnel Prism Intraocular Lens and Scharioth Macula Lens.

Survey of ophthalmology, 2018
Boon Lin Teh, R. Megaw, S. Borooah, B. Dhillon   +3 more
semanticscholar   +1 more source

Fresnel prisms and their effects on visual acuity and binocularity.

Transactions of the American Ophthalmological Society, 1979
1. 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 ...
openaire   +1 more source

Fresnel Formulas. Birefringent Prism

1973
M. ROUSSEAU, J.P. MATHIEU
openaire   +1 more source

An Evaluation of the Use of Fresnel Press-on Prisms in Childhood Strabismus

American Orthoptic Journal, 1975
S, Moore, L, Stockbridge
openaire   +2 more sources