摘要:
A progressive ophthalmic lens for the correction of myopia, that comprises an upper area in which the correction is adapted for peripheral vision of the wearer. Such a lens reduces the risk of long term worsening of myopia for the lens wearer by reducing the defocalisation of an image formed on the retina outside the foveolar area. Also disclosed is a method for making such a lens. According to one improvement, the correction of myopia for the peripheral vision in the upper area of the lens is further adjusted based on a tendency of the wearer to turn the eyes or the head for watching an eccentric object.
摘要:
A multifocal ophthalmic eyeglass (1) corrects a wearer's vision for a first vision distance in a principal vision zone (10) of the eyeglass, and for at least two different second vision distances in a secondary vision zone (20) of said eyeglass. For this purpose, the secondary vision zone is divided into at least two series of alternating regions, each producing an ophthalmic correction suitable for one of the second vision distances. A presbyopic wearer provided with such an eyeglass can both read a book and view an obstacle on the ground equally well, for the same direction of his gaze through the secondary vision zone.
摘要:
A method for producing an ophthalmic spectacle lens makes it possible to fit out a wearer of lenses in a manner which is customized as a function of a perception of blur by said wearer. The lens is selected so that the wearer has the impression of having a field of sharp vision which has a reference width. This reference width is determined on the basis of a first lens which complies with the wearer's ophthalmic prescription and a reference threshold value of the blur. It is thereafter associated within the lens which is provided for the wearer with a threshold value of the blur which is perceived by this wearer.
摘要:
The invention relates to the making of a progressive spectacle lens for customizing the lens based on the blur perception by a future lens wearer. Accordingly, a blur threshold value is determined for the wearer according to a blur perception criterion that varies based on an optical-power addition value prescribed for the wearer. The blur threshold value is associated with a reference sight direction for the lens provided to the wearer.
摘要:
An ophthalmic eyeglass (1) is adapted for correcting both the foveal vision and the peripheral vision of a wearer. An image portion formed in the foveal zone of the wearer's retina is thus sharp, at the same time as another image portion is also sharp, which is formed on the retina away from the foveal zone, by light rays that are oblique to the line of sight of the wearer. To this purpose, the eyeglass comprises a central zone (10) and first (21) and second (22) regions that alternate in a peripheral zone (20) of said eyeglass. First parameters of the eyeglass in the central zone and in the first regions are adapted so as to correct the foveal vision of the wearer and second parameters of the eyeglass in the second regions are adapted for correcting the peripheral vision of said wearer.
摘要:
The lens presents horizontal prismatic refractive power that varies progressively along the main progression meridian (MM′) with the addition of horizontal prismatic power being greater than 2 prismatic diopters in absolute value, this addition of horizontal prismatic power being defined by the difference between the horizontal prismatic refractive power at the reference point (L) of the far vision zone and the horizontal prismatic refractive power at the projection point (P′) of the reference point (P) of the near vision zone (VP) on the vertical line passing through the reference point (L) of the far vision zone.
摘要:
The invention relates to a method for characterizing a perception of blur by a subject (10) in order to determine a dioptric blur value for an image (C) observed by the subject. The image has a blur generated by the low-pass filtering of the image components in accordance with the respective space frequencies of said image components. An indication of the perception thereof of blur in the image is provided by the subject and is associated with the dioptric blur value. Several images associated with different dioptric blur values are used for defining a dioptric blur threshold value for the subject that corresponds to a blur perception criterion. The invention can be used for adjusting the design of a progressive lens for the subject in accordance with the sensitivity to said visual blur of said object.
摘要:
The invention relates to a method for characterizing a perception of blur by a subject (10) in order to determine a dioptric blur value for an image (C) observed by the subject. The image has a blur generated by the low-pass filtering of the image components in accordance with the respective space frequencies of said image components. An indication of the perception thereof of blur in the image is provided by the subject and is associated with the dioptric blur value. Several images associated with different dioptric blur values are used for defining a dioptric blur threshold value for the subject that corresponds to a blur perception criterion. The invention can be used for adjusting the design of a progressive lens for the subject in accordance with the sensitivity to said visual blur of said object.
摘要:
The invention relates to the making of a progressive spectacle lens for customizing the lens based on the blur perception by a future lens wearer. Accordingly, a blur threshold value is determined for the wearer according to a blur perception criterion that varies based on an optical-power addition value prescribed for the wearer. The blur threshold value is associated with a reference sight direction for the lens provided to the wearer.
摘要:
A progressive ophthalmic lens for the correction of myopia, that comprises an upper area in which the correction is adapted for peripheral vision of the wearer. Such a lens reduces the risk of long term worsening of myopia for the lens wearer by reducing the defocalisation of an image formed on the retina outside the foveolar area. Also disclosed is a method for making such a lens. According to one improvement, the correction of myopia for the peripheral vision in the upper area of the lens is further adjusted based on a tendency of the wearer to turn the eyes or the head for watching an eccentric object.