Patent ID: 8807747

Claim:
A spectacle eyeglass for a myopic child, comprising: a lens of progressive addition type so as to produce variations in optical power and astigmatism values when an eye direction is varying through the lens for a user of said lens, said lens having a fitting cross configured to be located in front of an apex of the user's eye when the lens is fitted into a spectacle frame and worn by the user, for the user looking ahead horizontally with his head in vertical position, said lens having a channel having two side limits defined by eye directions with 0.5 diopter residual astigmatism, and a meridian line of said lens being equally distant from said channel limits in planes corresponding to a constant declination angle, a lower part of said meridian line being offset laterally with respect to a vertical plane when the lens is rotated so that upper extensions of the channel side limits extend symmetrically in lateral angular height with respect to said vertical plane, respectively towards left and right sides of the lens, the lens having an optical power increasing along the meridian line, downwards below an upper reference eye direction oriented above a primary eye direction within the vertical plane, said primary eye direction passing through the fitting cross, and said upper reference eye direction corresponding to a point in the lens where the optical power for the far vision is to be measured, wherein the following conditions are met: /i/ the variation in the optical power between the upper reference eye direction and a lower reference eye direction crossing the meridian line with a declination angle value of 21° below the primary eye direction is comprised between 1.25 and 2.75 diopters, including these limit values; /ii/ the variation in the optical power between the upper reference eye direction and the primary eye direction is less than 0.2 diopter; /iii/ an offset of the meridian line is higher than 5.5°, said offset being an angular distance between the vertical plane and the lower reference eye direction, measured in a plane of constant declination angle containing said lower reference eye direction.