Optics: eye examining – vision testing and correcting – Spectacles and eyeglasses
Reexamination Certificate
2001-07-18
2003-01-14
Mai, Huy (Department: 2873)
Optics: eye examining, vision testing and correcting
Spectacles and eyeglasses
C351S154000
Reexamination Certificate
active
06505930
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to spectacle frames of the wrap-around or shield type, in particular frames adapted to receive optical lens of unconventional shape, and to optical lens elements for mounting in frames.
BACKGROUND AND OBJECTS OF THE INVENTION
It is known in the prior art to manufacture non-corrective eyeglasses such as sunglasses or protective eyeglasses having wrap-around segments designed to shield the eye from incident light, wind, and foreign objects in the temporal vision field of the wearer.
SUMMARY OF THE INVENTION AND PREFERRED EMBODIMENTS
Visible light and light in the UV region may enter the eye from angles as high as 100° from the line of sight.
It has not been possible, however, in prior art sunglasses or protective eyeglasses, to provide such spectacles with significant refractive power, whilst maintaining a cosmetically acceptable appearance. The radius of curvature required to provide an ophthalmic lens including a prescription surface is such that the spectacles would produce a bug-eyed appearance, which would be cosmetically unacceptable.
Further, in International Patent Application PCT/AU97/00188 “Improved Single Vision Lenses”, Applicants disclose an optical lens element including a front and back surface, at least one surface being continuous, and forming a prescription (Rx) zone and a peripheral temporal zone for providing a shield in the area of the temples, which zones are smoothly blended to avoid a prismatic jump from the Rx zone to the temporal zone.
In International Patent Application. PCT/AU98/00274 “Lenses and Spectacles Bearing Lenses”, to Applicants, the entire disclosure of which is incorporated herein by reference, Applicants disclose an ophthalmic article including an optical lens element including a front and back surface, at least one surface being continuous, and forming a prescription (Rx) zone and optionally a non-prescription peripheral temporal zone, at least one surface exhibiting a change of base curve across the field of vision of the wearer; the front and/or back surface bearing a surface correction to at least partially adjust for optical errors.
Whilst such lenses are a significant improvement, it is necessary to provide spectacle frames which will receive such unusually shaped lenses.
It is accordingly an object of the present invention to overcome, or at least alleviate, one or more of the difficulties and deficiencies related to the prior art.
Accordingly, in a first aspect of the present invention there is provided a spectacle frame shaped to receive and retain an optical lens element of the wrap-around or shield type wherein the aperture of the lens outline or edge of at least one surface of the optical lens element is of generally ovaline shape and is located on the surface a sphere whose radius of curvature corresponds to 11 Dioptre (D) or above, a toroid where the horizontal radius or curvature corresponds to 11 D or above, or a surface where the radius of curvature changes across at least one section of the lens aperture.
Such frames differ significantly in curvature from frames known in the prior art.
By the term “an optical lens element of the wrap-around or shield type”, we mean that at least one surface of the optical lens falls on a topographical surface that wraps around the human visual apparatus or forms a facial shield.
Preferably the radius of curvature corresponds to 12 D or above, more preferably at least 16 D, most preferably at least 20 D.
The optical lens element may be removably or permanently attached to the frame.
In a preferred form the spectacle frame is itself attached to a sunglass having zero refractive power.
The optical lens element may bear a prescription surface of minus or plus power or may be piano and is preferably suitable for industrial safety or contact sport applications.
The spectacle frame according to this aspect of the present invention may be of any suitable type. The spectacle frame may permit adjustment of the inter-pupillary distance for example via attachment of a lens to the frame supports. Frames of the rimless and temple bar type may be used.
In a preferred form, the front surface of the optical lens element exhibits a change of base curve across the field of vision of the wearer, the base curves being smoothly blended to avoid a prismatic jump in the Rx zone.
By the term “lens element” as used herein, we mean an optical or ophthalmic lens, semi-finished lens, or lens wafer which may be utilised in the formation of an ophthalmic product.
By the term “optical lens element” as used herein, we mean an optical or ophthalmic lens, semi-finished lens or lens formed from a pair of lens wafers which may be utilised in the formation of an optical lens product.
In a preferred embodiment of the present invention, at least one surface of the optical lens element is located on the surface of a toroid where the horizontal radius of curvature corresponds to 11 D or above and the vertical radius of curvature is at least 3 D less than the horizontal curvature.
In a further preferred embodiment where the lens aperture outline falls on a surface, and the radius of curvature changes across a section of the lens aperture, the change in curvature corresponds to 3 D or more. Preferably the change in curvature extends across the entire lens aperture.
In a still further preferred embodiment of the present invention, there is provided a spectacle frame shaped to receive and retain an optical lens element of the wrap-around type wherein the aperture of the lens outline or edge of at least one surface of the optical lens element is of generally ovaline shape and is located on a surface whose radius of curvature varies across the vertical or horizontal sections of the aperture of the lens outline, or both the vertical and horizontal sections thereof.
The change may for example correspond to 3 D or more horizontally and 2 D or more vertically.
The changes in curvature may be distributed smoothly across the aperture of the lens outline. The changes in curvature for example, may occur across the field of direct (forward) vision of a wearer, that is within 55° of the line of sight for distance vision. Alternatively, the change in curvature may occur across the line of sight and within the cone of foveal vision; that is, approximately 25° either side of the line of sight.
In a further alternative, the change of curvature may occur in the off-axis field of binocular vision, that is approximately 25° to 55° either side of the line of sight of the wearer. Still further the change in curvature may occur in the off-axis peripheral field, that is more than 55° away from the line of sight of the wearer.
The changes in curvature may be viewed as asymmetric with respect to the line of sight. For example the curvature may increase in the temporal direction horizontally from nasal limit toward the peripheral viewing field or increase in down gaze vertically from the eye brows to the limits set by nose and cheek intrusion into the visual field. Alternatively the vertical and/or horizontal curvatures remain constant from the line of sight to the visual limits corresponding to brow or nasal intrusion on the visual field. The vertical and/or horizontal curvatures may remain constant from the nasal or brow limits to approximately 25° temporal or down-gaze from the line of sight. For example the temporal curvature is constant to approximately 55° from the line of sight.
In a further preferred aspect, the change in curvature across the aperture of the lens outline is 6 D or more in lens power equivalent, preferably 9 D or more, more preferably 12 D or more.
In a preferred aspect of the present invention, there is provided a spectacle frame shaped to receive and retain an optical lens element of the wrap-around or shield type wherein the aperture of the lens outline or edge of at least one surface of the optical lens element is of generally ovaline shape and remains substantially constant irrespective of lens power.
The spectacle frame may further include a removable or adjustable bridge or n
Morris Michael Alan
Perrott Colin Maurice
Burns Doane , Swecker, Mathis LLP
Mai Huy
Sola International Holdings Ltd.
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