| 摘要 |
A polarized optical element is disclosed comprising an upper portion and a lower portion defined at opposite parts with respect to a median line passing through the geometric center of the optical element, wherein: a) in the upper portion and at a distance of at least 10 mm from the median line the factor of luminous transmittance is between 3% and 20%; b) in the lower portion and at a distance of at least 10 mm from the median line the factor of luminous transmittance is between 15% and 65%; c) the ratio of the luminous transmittance measured in the lower portion at a distance of at least 10 mm below the median line and the luminous transmittance measured in the upper portion at a distance of at least 10 mm above the median line is not lower than 1.5; d) the colors of the upper and lower portions of the optical element are such that: d1) the absolute value of the difference between the value of the colorimetric coordinate a* of the upper portion measured at a point located 10 mm above the median line and the value of the colorimetric coordinate a* of the lower portion measured at a point located 10 mm below the median line is comprised between 0 and 60, d2) the absolute value of the difference between the value of the colorimetric coordinate b* of the upper portion measured at a point located 10 mm above the median line and the value of the colorimetric coordinate b* of the lower portion measured at a point located 10 mm below the median line is comprised between 0 and 60, e) the degree of polarization of the optical element is uniform both along a vertical and along a horizontal direction and is equal to at least 45% as measured according to European Standard EN 1836.
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