Abstract: A lighting device includes a light source unit that outputs light, an elongated light guide including a first end surface on which the light is incident, a second end surface located opposite to the first end surface, an emitting surface, and at least one held portion provided on at least one of the longitudinal side surfaces different from the emitting surface, the light guide guiding the light from the first end surface to the second end surface, and a housing including an attachment portion to which the light source unit is attached, a housing portion that is open at an end portion on the attachment portion side and includes a housing recess to house the light guide and an exposure opening exposing the emitting surface, and a holding portion that holds the light guide in the housing recess by sandwiching the at least one held portion.

Abstract: A progressive power eyeglass lens is disclosed. The lens is particularly suitable for close-range work while facilitating distinct vision up to a specific distance that is substantially separated from the close-view distance. The lens also provides a wide distinct-vision area in the near-vision region. The lens comprises a near-vision correction region with a surface refractive power suitable for near vision, a specific-distance-vision correction region with a surface refractive power suitable for a specific distance that is substantially separated from the close-view distance, and a progressive zone between the near-vision correction region and the specific-distance-vision correction region that provides a gradual change in refractive index from the near-vision correction region to the specific-distance-vision correction region.

Abstract: A progressive lens including, along a principal meridional line dividing a refracting surface of the lens into a nasal side area and a temporal side area, a far viewing portion having a surface refracting power corresponding to a far view, a near viewing portion having a surface refracting power corresponding to a close-range view, and an intermediate viewing portion continuously connecting the refracting powers of the two portions together between the far viewing portion and the near viewing portion, a distance along the principal meridional line between a far viewing center of the far viewing portion and a near viewing center of the near viewing portion being within 18 mm, a width of a clear vision area in the near viewing portion being greater than or equal to a width of a clear vision area in the far viewing portion.

Abstract: A progressive power lens comprising, along a principal meridional curve dividing a lens refracting surface into a nasal side region and a temporal side region, a portion for distant vision having a refracting power corresponding to a distant view, a portion for near vision having a refracting power corresponding to a near view and an intermediate portion, located between the portion for distant vision and the portion for near vision, for continuously connecting the refracting powers of the portions for distant and near vision, wherein the principal meridional curve is displaced with respect to a vertical direction in the state with the lens worn toward the nasal side in the intermediate portion and the portion for near vision, and an astigmatic difference distribution in a horizontal direction in the worn state is symmetrical with respect to the principal meridional curve in the intermediate portion and asymmetrical with respect to the principal meridional curve in the portion for near vision.

Abstract: A progressive power lens of the present invention comprises, along a principal meridional curve, a portion for distance vision having a refracting power corresponding to a distant view, a portion for near vision having a refracting power corresponding to a near view and an intermediate portion, located between the portion for distance vision and the portion for near vision, for continuously connecting the refracting powers of the portion for distance vision and the portion for near vision. When an average refracting power (diopter) of a lens refracting surface at a center for distance vision is S.sub.0 and an additional power of said lens refracting surface is A.sub.D, from a center for distance vision to lateral side areas of the center for distance vision in a worn state, when a mean power (diopter) of each point of the lens refracting surface is S.sub.E and the difference between the mean power S.sub.E of each point of the lens refracting surface and the mean power S.sub.

Abstract: In a progressive multifocal lens of the present invention, the horizontal sectional shape of a refracting surface of the lower portion of a farsight portion defines a non-circular arc in which a horizontal section curvature is increased and then decreased away from an intersecting point with the principal meridional curve along a horizontal crossing curve, the horizontal sectional shape of a refracting surface of the upper portion of a nearsight portion defines a non-circular arc in which a horizontal section curvature is decreased and then made approximately constant away from an intersecting point with the meridional curve along a horizontal crossing curve, the gradient of the decrease of a horizontal section curvature is approximately constant from the upper portion of the nearsight portion to the lower portion thereof, the horizontal sectional shape of a refracting surface of the center of an intermediate portion in which a horizontal section curvature is decreased away from an intersecting point with the

Abstract: A progressive multifocal lens of the present invention has, along a principal meridional curve, a farsight portion having a refracting power corresponding to a distant view, a nearsight portion having a refracting power corresponding to a near view, and an intermediate portion, located between the farsight and nearsight portions, for continuously connecting the refracting powers of the farsight and nearsight portions, wherein a refracting surface has a shape such that the angle .theta. formed by normal lines of the refracting surface at respective points on each of vertical crossing curves of the lens refracting surface and a principal meridional curve is changed gently and monotonously away from the principal meridional curve along the respective vertical crossing curves in a direction perpendicular to the principal meridional curve.

Abstract: In a progressive multifocal lens of the present invention, the values of a curvature .rho.m of a refracting surface along the principal meridional curve and a curvature .rho.s of the refracting surface in a direction perpendicular to the principal meridional curve become maximum at approximately the center of a nearsight portion on the principal meridional curve, decrease toward the peripheral region of the nearsight portion along the principal meridional curve, are substantially different from each other at least from the lower portion of a farsight portion to approximately the center of a intermediate portion, are substantially equivalent from approximately the center of the intermediate portion to the lower portion of the intermediate portion, and are substantially different from each other from the lowest portion of the intermediate portion and the nearsight portion.