Patent ID: 8529063

Claim:
A pair of ophthalmic spectacles, comprising: two lenses; a frame configured to hold and respectively position the two lenses in front of corresponding eyes of a wearer of said spectacles, and allow separate vision for the wearer through each lens, said pair of spectacles including for each lens: at least one radiation source configured to produce radiation to be reflected by the sclera and by the iris of the corresponding eye of the wearer in accordance with different reflection intensity coefficients respectively for the sclera and the iris; at least one detector configured to measure respective intensities of portions of the radiation produced by the source, respectively reflected in ocular areas, of a border between the sclera and the iris of the corresponding eye, that move about during eye movements, each ocular area being in a left portion or a right portion of the border; and at least four radiation output or input sections arranged in the lens, each output section being arranged to direct a portion of the radiation produced by the source towards at least one of said ocular areas, and each input section being arranged to collect a portion of the radiation reflected in one of said ocular areas, so as to form at least four radiation paths which each comprise a reflection on the eye corresponding to said lens, in one of the ocular areas in which the right and left portions, for their respective paths, of the border between the sclera and the iris of said eye move about; a means for separating the portions of radiation transmitted between said at least one radiation source and said at least one detector by different respective radiation paths; and a computation unit configured to characterize a convergence of the eyes of the wearer at a common observation point, as a function of the intensities which are simultaneously measured for the two lenses, wherein for each lens, said at least one source, said at least one detector, and said at least four radiation output sections or input sections are arranged to form at least two pairs of distinct paths for the radiation, with two first radiation output sections arranged in each lens at a same first elevation, and two second radiation output sections arranged in each lens at a second elevation which is different from said first elevation, the ocular areas in which the right and left portions, for the respective paths of each pair, of the border between the sclera and the iris of the corresponding eye, are positioned at a same ocular area elevation which is associated with said pair, the two pairs of paths being associated with respective ocular area elevations which are distinct from each other and common to the two lenses, and the computation unit is configured to characterize the convergence of the eyes of the wearer as a function of the intensities measured simultaneously for the portions of radiation transmitted by the paths associated with a same ocular area elevation, selected by said computation unit for the two lenses.