Abstract:
A series of progressive ophthalmic lenses is proposed, which is indexed by optical power addition values of glasses of spectacles to be made from these lenses. Each lens of the series determines a further gap between a value of the optical power for the near vision direction and a maximum value of the optical power which is obtained for a direction of gaze pointing below said near vision direction. The lenses of the series are adapted for postures of wearers that may vary as a function of the optical power addition values.
Abstract:
The invention relates to a lens with a horizontal prismatic refractive power which varies progressively along the principal meridian of progression (MM') with an addition of horizontal prismatic power greater than 2 prismatic dioptres in absolute terms. This addition of horizontal prismatic power is defined by the difference in power of horizontal prismatic refraction at a reference point (L) in the distant field of vision and the power of horizontal prismatic refraction at the point (P') of projection of the point of reference (P) in the near field of vision (VP) onto the vertical passing through the point of reference (L) of the distant field of vision.
Abstract:
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 subject.
Abstract:
The invention relates to a method for producing a novel progressive glasses lens intended for a presbyopic wearer (100), which takes into account the postural habits of the wearer, acquired through prior conditions of ophthalmic correction (102). A design for the novel progressive lens is established by modifying a reference lens in compliance with an aptitude of the wearer to modify his/her postural habits. To this end, variations in a postural parameter are determined using measurements of said parameter, which are carried out on the wearer. The invention enables the reduction of a period of habituation by the wearer to the novel progressive glasses lens.
Abstract:
The method involves obtaining an ametropia correction of a wearer for a vision distance, and other ametropia corrections of the wearer for other vision distances. Principal and secondary vision zones (10, 20) of an eyeglass are determined. The secondary zone is divided into two sets of regions (21, 22). Parameters of the eyeglass in the principal vision zone are determined. Other parameters of the eyeglass in the regions of one set are determined based on one of the latter ametropia corrections and assigned to the set of regions. The eyeglass is produced according to the parameters. An independent claim is also included for a multifocal ophthalmic lens forming a finished or semi-finished eyeglass, comprising principal and secondary vision zones.
Abstract:
The present invention relates to an ophthalmic lens, having, on its surface, a colorless or yellow, central first zone and at least one peripheral second zone, selectively transmitting visible light having a wavelength of less than 570 nm.