Results 241 to 250 of about 38,101 (289)
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Effect of Rigid Gas Permeable Lens Flexure on Vision
Optometry and Vision Science, 1992The flexure of spherical rigid lenses (various materials) and a soft lens was measured using automated over-keratometry on 6 adapted rigid lens wearers (12 eyes) whose corneal toricity ranged from 1.37 to 3.87 D. The results showed: (1) that there was no significant difference in flexure between polymethyl methacrylate (PMMA), silicone acrylate, and ...
L, Sorbara, D, Fonn, K, MacNeill
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Tear Layer Thickness Characteristics of Rigid Gas Permeable Lenses
Optometry and Vision Science, 1986The tear layer thickness profiles of two groups of clinically successful wearers of rigid contact lenses were calculated from the measured anterior corneal surface and posterior contact lens surface characteristics. These profiles showed good agreement with their theoretical values for all parameters considered.
M, Guillon, D P, Lydon
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Ocular Characteristics Associated with Rigid Gas-Permeable Lens Adherence
Optometry and Vision Science, 1996Rigid gas-permeable (RGP) lens adherence after overnight lens wear is clearly a patient-dependent phenomenon. However, no previous study has attempted to determine whether specific ocular characteristics are associated with an increased frequency of lens adherence.In this study, clinically applicable tests were used to measure a range of ocular ...
H A, Swarbrick, B A, Holden
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Rigid gas permeable contact lenses: Out in the cold
Contact Lens and Anterior Eye, 2009Rigid gas permeable (RGP) contact lens wearers may experience episodes of lens fracture during handling. In this paper, we report the case of a keratoconic contact lens wearer whose lens fractured whilst being handled at sub-zero temperatures. Subsequent studies illustrate how PMMA and RGP contact lenses behave when exposed to sub-zero temperatures ...
A Jonathan, Jackson, Clive J, Wolsley
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Rigid Gas-Permeable Lens Adherence: A Patient-Dependent Phenomenon
Optometry and Vision Science, 1989Ten unadapted subjects participated in a study to investigate the incidence and intrasubject repeatability of rigid gas-permeable (RGP) lens binding (adherence) over a 7-day period of overnight lens wear. An overall incidence of lens binding of 49% was found, based on subject self-assessment on eye opening.
H A, Swarbrick, B A, Holden
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Factors Influencing Vision with Rigid Gas Permeable Alternating Bifocals
Optometry and Vision Science, 1989This study assessed the fitting and visual performance of a rigid, gas permeable (RGP), monocentric, alternating bifocal. Fourteen presbyopic eyes each wore 24 different lenses consisting of all combinations of 2 diameters, 2 segment heights, 2 prism ballasts, and 3 fitting relations.
K S, Ames +3 more
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Rigid gas permeable lenses and patient management.
The CLAO journal : official publication of the Contact Lens Association of Ophthalmologists, Inc, 1989The introduction of new rigid gas permeable (RGP) contact lens materials provides the practitioner with a number of alternatives for patient management. But whatever the lens materials used, problems related to the lenses, care and maintenance solutions, and patients may arise.
R, Terry, C, Schnider, B A, Holden
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Diagnostic bitoric rigid gas permeable contact lenses.
The CLAO journal : official publication of the Contact Lens Association of Ophthalmologists, Inc, 1999To simplify the fitting of bitoric rigid gas permeable (RGP) contact lenses.We prescribed bitoric RGP lenses using two kinds of diagnostic lenses at random. One type of lens was a diagnostic polymethylmethacrylate (PMMA) spherical lens and the other was a diagnostic RGP bitoric lens.The bitoric RGP lenses that were prescribed using a diagnostic bitoric
M, Kajita +4 more
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Rigid gas‐permeable contact lenses
Clinical and Experimental Optometry, 1987openaire +2 more sources
Complications of Rigid Gas Permeable Lenses for Extended Wear
Optometry and Vision Science, 1991A retrospective study of 174 patients wearing rigid gas permeable lenses for a period of 2 years was carried out to determine the success rate and types of complications which typically occur. The results indicate that these types of lenses are a viable modality for extended wear, as the majority of signs which may lead to serious complications can be ...
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