A partir de cette page vous pouvez :
Retourner au premier écran avec les dernières notices... |
Détail de l'auteur
Auteur Gerald Westheimer
Documents disponibles écrits par cet auteur
Ajouter le résultat dans votre panier Affiner la rechercheObjective Measures of Retinal Image Degradation Due to Refractive Corrections / Gerald Westheimer in OVS : Optometry & Vision Science, vol. 98, 06 (Juin 2012)
[article]
in OVS : Optometry & Vision Science > vol. 98, 06 (Juin 2012)
Titre : Objective Measures of Retinal Image Degradation Due to Refractive Corrections Type de document : article de périodique Auteurs : Gerald Westheimer Année de publication : 2021 Langues : Français (fre) Descripteurs (mots clés) : [Thésaurus Mesh]Rétine
[Thésaurus Mesh]Troubles de la visionMots-clés : dégradation de l'image rétinienne Résumé : SIGNIFICANCE: There is a need for a measure, as simple and yet as informative as possible, to describe objectively the retinal image quality when a patient views targets at various distances through spectacle, contact, or intraocular corrections with optics more elaborate than single vision. PURPOSE: The purposes of this study are to examine the current status of quantitative descriptions of retinal image blur and find optimal characterization of image degradation. METHODS: A variety of indexes of image degradation are computed for a typical eye and polychromatic light, in and out of focus, and as exemplars of sophisticated wave shaping, when the pupil transmission has been modified to a truncated Bessel amplitude function and to a “fractal” phase function. RESULTS: Figures are shown for the optical transfer, point- and edge-spread functions, and Koenig bar and optotype letter blur for the various imaging and defocus conditions, and the relative values of several blur indexes are compared graphically and in a correlation table. CONCLUSIONS: No single index captures the many ways in which the image can deviate from the diffraction-limited ideal. Among the incomplete descriptors of image degradation, the light distribution at a sharp edge stands out as optimally informative and economical, and, when condensed to just two values, one representing central image sharpness and the other outlying light spread, allows for a quick survey of the imaging deficit. Permalink : https://bibliotheque.helb-prigogine.be/opac_css/index.php?lvl=notice_display&id= [article]Exemplaires
Cote Support Localisation Section Disponibilité aucun exemplaire Topical Review: Pilocarpine-induced Miosis as Help for Early Presbyopes? / Gerald Westheimer in OVS : Optometry & Vision Science, vol. 99, 08 (Aout 2022)
[article]
in OVS : Optometry & Vision Science > vol. 99, 08 (Aout 2022)
Titre : Topical Review: Pilocarpine-induced Miosis as Help for Early Presbyopes? Type de document : article de périodique Auteurs : Gerald Westheimer Année de publication : 2022 Langues : Français (fre) Descripteurs (mots clés) : [Thésaurus Mesh]:A:Acuité visuelle:Acuité visuelle / effets des médicaments et des substances chimiques
[Thésaurus Mesh]:P:Presbytie:Presbytie / thérapie
[Thésaurus Mesh]Pilocarpine
[Thésaurus Mesh]Presbytie
[Thésaurus HELB]:Optique:solution ophtalmiqueRésumé : SIGNIFICANCE: The clinical utility of ophthalmic pilocarpine-induced pupil constriction to help overcome image blur of close-up targets in patients with failing accommodation is examined. Pilocarpine in low-concentration ophthalmic solution eye drops constricts the pupil to approximately 2 mm and thus reduces defocus blur. To gain regulatory approval of this drug for the treatment of presbyopia, clinical trials were conducted with 1.25% pilocarpine. Near vision was improved in a modest proportion of early presbyopes: between 12 and 22% more patients reached criterion near visual acuity than with a placebo, depending on conditions. The drug is well tolerated, and its effect has onset of only minutes and lasts several hours. Small pupils will cause diminished night vision and may have an impact on distance acuity to which possible minor drug-induced accommodative spasms could contribute. The therapy has a role for patients who want to postpone or briefly pause dioptric supplementation of their failing accommodation. No convincing case has been made for one version of ophthalmic pilocarpine over another. Permalink : https://bibliotheque.helb-prigogine.be/opac_css/index.php?lvl=notice_display&id= [article]Exemplaires
Cote Support Localisation Section Disponibilité aucun exemplaire