Abstract: The invention relates to a multifocal ophthalmic lens, comprising an aspherical surface with a mean sphere and a cylinder at every point thereof, characterized by the equation: L<1/(−0.031×R2+0.139×R+0.014) where L is equal to the ratio (Smax−Smin)/gradSmax, the ratio of the difference between the maximum and minimum values of the mean sphere in a region of a 40 mm diameter circle centered on the geometric center of the lens, this region being limited by vertical straight lines at 1 mm from this center on the temporal side and at 4 mm from this center on the nasal side, on the one hand, to the maximum value of the gradient of the mean sphere in this same region, on the other hand, and where R is equal to the ratio Cmax/(Smax−Smin), the ratio of the maximum cylinder value inside said circle to the difference between the maximum and minimum values of the mean sphere in said region.

Abstract: The invention provides an apparatus and a method for measuring the geometrical structure of an optical component (2) in transmission, comprising the steps:

Abstract: The invention relates to a multifocal ophthalmic lens, comprising an aspherical surface with a mean sphere and a cylinder at every point thereof, characterized by the equation:

Abstract: The invention relates to a method for fitting, in a frame, a progressive ophthalmic lens prescribed for a wearer. It proposes that only the horizontal position of the wearer's pupil be measured on the wearer. From this measurement, and from the total height of the pattern of the frame, the lens is positioned in the frame, and is then machined and fitted into the frame.

Abstract: A method is provided for determining, by optimization, an ophthtalmic lens for a spectacle wearer for whom an astigmatism has been prescribed, comprising the steps of: selecting a starting lens and defining a working lens to be equal to the starting lens; selecting a target lens; modifying the working lens, in order to minimize, in a plurality of directions of glance and in a reference frame associated with the eye differences in power between the working lens and the target lens and differences between astigmatism prescribed and astigmatism generated by the working lens. The invention makes it possible to avoid aberrations introduced, for an astigmatic spectacle wearer, by adding a toric surface having the prescribed astigmatism, thereby ensuring that the astigmatism effectively experienced by the wearer is the prescribed astigmatism.

Abstract: There is provided a spectacle frame 1, having a least one corrective lens the characteristics of which do not vary over time and having telemetry means 5 which set off an alarm 9, 10 when the distance measured by the telemetry means is less than a predetermined preference distance. This reference distance can for example be set at between 20 and 50 cm depending on the spectacle wearer. A kit is also provided comprising a frame, telemetry means and an alarm. The spectacle frame can be prescribed for slowing down the evolution of acquired myopia in children who are starting to acquire myopia; here, the spectacle frame is provided with progressive multifocal lenses. The telemetry means and alarm incite the child to respect a sufficient working distance for close vision.

Abstract: A multifocal ophthalmic lens comprising a far vision region, a near vision region and an intermediate vision region is provided having a high near vision region and a wide vision field in the near vision region, the intermediate vision region and in the far vision region. Progression is gentle although the distance between a mounting center on the lens and the point where power addition is 85% higher than power addition at a far vision control point is less than 16 mm, while simultaneously maximum cylinder inside a 20 mm radius circle centered on a geometrical center of the lens is kept at a low value.

Abstract: In a progressive multifocal ophthalmic lens providing excellent performance in the far vision region, good width of the near vision region and gentle progression in the intermediate vision region therebetween, the far vision region comprises an angular sector defined by two half-lines that intersect at the geometrical center of the lens forming an upwardly-directed angular segment with an included angle of preferably more than 145.degree. in which all points have a cylinder less than A/2 diopters, and constraints are applied governing the gentleness of progression in the intermediate vision region and the relative width of the near vision region.

Abstract: A method and device for measurement of the geometrical or optical structure of an optical component such as a lens or a mold for making lens are provided. The method comprises the steps of illuminating the optical component to be measured with incident light having a known wavefront, measuring, in a given plane, the maps of the wavefront slopes of the light, after reflection at or transmission by the optical component, and deducing the surface topography or refraction index map of the optical component to be measured from the measurements of the slope maps by the application of at least one calculating procedure.