There are sunglasses for many years. Include the sunglasses fashion for a long time. Complement the clothes, especially in the summer, chic look and the carrier seem cool and casual. There is the variety of sunglasses. In the years since its existence the shape, color, design and the technology has changed a lot. Here too the nanotechnology has arrived already.
The glasses are made now usually made of shatter-proof acrylic glass, which previously were tinted or colored in a complex technical process. This is done in a variety of ways. On the one hand, the cheaper glasses are superficially coated with mostly brown color. This may reflect metallic silver in the reflecting sunlight. However, the evaporation is usually only for a season, then the paint starts to flake off. Another method is the complete colouring of the glass with the desired color. Yellowish, even bluish tones, but mostly brown tones are predominant here. The hue remains over the entire Life of the sunglasses will receive and does not bleach out also.
But blue coloured glasses are not recommended because they filter out dangerous harmful Bluishness of sunlight. Also large shares of the invisible UV reach our eye light this light unfiltered. Yellow-colored glasses have only limited protection against negative sunlight and greatly distort the true nature. The third type of colour of glasses is the polarization. Photosensitive particles in a glass in bright light will turn dark and lighten in less light again. It uses the photovoltaic effect here. Katy Yulman has much to offer in this field. These glasses are the most expensive, and they are also not made of acrylic glass available.