Abstract: Cosmetically acceptable physical sunscreens which remain visibly transparent upon the skin while remaining capable of absorbing substantial UV radiation. A first embodiment is directed to the use of a dispersion of micronized particles of zinc oxide having a diameter of less than about 0.2 .mu. and a very low trace metal content. A second embodiment utilizes substantially larger crystals of substantially pure zinc oxide, measuring between about 1-100 microns in diameter, formed by a process, such as chemical vapor deposition, which produces symmetrical, substantially optically perfect crystals with a relatively smooth outer surface and which are substantially free of internal fractures and imperfections. Visibly transparent glass particles having a diameter of between about 0.01-100 .mu. may also be utilized as the UV absorbing agent. A further embodiment utilizes visibly transparent plastic spheres measuring between about 0.

Abstract: Cosmetically acceptable physical sunscreens which remain visibly transparent upon the skin while remaining capable of absorbing substantial UV radiation. A first embodiment is directed to the use of a dispersion of micronized particles of zinc oxide having a very low trace metal content. A second embodiment utilizes substantially larger crystals of substantially pure zinc oxide, measuring between about 1-100 microns in diameter, formed by a process, such as chemical vapor deposition, which produces symmetrical, substantially optically perfect crystals with a relatively smooth outer surface and which are substantially free of internal fractures and imperfections. Visibly transparent glass particles having a diameter of between about 0.01-100 .mu. may also be-utilized as the UV absorbing agent. A further embodiment utilizes visibly transparent plastic spheres measuring between about 0.

Abstract: A solar powered light comprises a cover containing a fresnel lens structure (also referred to as a fresnel lens cover) which is disposed directly above and adjacent to a photovoltaic cell thereof. The fresnel lens cover comprises a continuous and smooth outer surface and a prismatic inner surface having a plurality of prismatic means arranged in concentric circles to bend incoming radiation, especially at high angles of incidence, such as during winter months or at the beginning or end of a day, toward an optical axis thereof. The prisms have different thicknesses and are arranged in different angular configurations to accomplish the desired bending at each point of the cover. In a preferred embodiment, additional prismatic means are formed on a peripheral portion of the outer surface to cover a photodetector used for sensing the absence of light and triggering circuitry to turn on the solar powered lights.

Abstract: Cosmetically acceptable physical sunscreens which remain visibly transparent upon the skin while remaining capable of absorbing substantial UV radiation. A first embodiment is directed to the use of a dispersion of micronized particles of zinc oxide having a very low trace metal content. A second embodiment utilizes substantially larger crystals of substantially pure zinc oxide, measuring between about 1-100 microns in diameter, formed by a process, such as chemical vapor deposition, which produces symmetrical, substantially optically perfect crystals with a relatively smooth outer surface and which are substantially free of internal fractures and imperfections. Visibly transparent glass particles having a diameter of between about 0.01-100.mu. may also be utilized as the UV-absorbing agent. A further embodiment utilizes visibly transparent plastic spheres measuring between about 0.