Various designs and colors of sunglasses and not always easy to choose the right ones for every need, here a guide to buying sunglasses. The use of glasses have evolved from the fifteenth century, when they were used by the judges in the courts to avoid showing their expressions. Later they became a fashion accessory, adopted different brands, and each year draw new models and colors, designed to complement the look and protect the eyes from the sun. However at present, have also become, an object necessary to avoid damage caused by sunlight.
How to choose the right kind of glasses?
The first thing to consider is the type of face, the overall face shape and the shape of the glasses will be opposed:
– Round face: You should always avoid the curved lines on the glasses, so as not to accentuate the roundness of the face. Ideal lenses are large, rectangular, broad and strong colors in the frame.
– Oval face: This type of face you can use any style of lenses, as long as not too thin, to avoid extending too much face.
– Triangular face or heart: The glasses are perfect oval or round with a slim frame, in order to decrease the angle of the face.
– Square face: In this type of face soften the angles for the face, making them ideal glasses at the bottom and rounded corners.
Choosing the right lens color for every occasion:
Once you have defined the type of glasses, you should consider the use to which they give and the type of light that will take care to choose the color that best suits.
– Blue lenses: They are not practical or useful as they block the light amber, red and blue, causing a false perception of colors that makes them unsuitable for various activities of daily living.
– Green lenses: This tone was used by the company Bausch & Lomb for glasses made for pilots, and are perfect for driving in normal conditions.
– Gray lenses: This color is pretty basic, you can take almost any time, offering a correct perception of colors.
– Amber or yellow lenses: Are the colors appropriate for situations where there is fog or low light by filtering blue light, making it difficult to focus properly.
– Brown lenses: Its properties are similar to gray, with the difference that the brown lenses allow you to filter some blue light, causing a greater contrast.
Existing standards in the sunglasses:
Because the primary purpose of sunglasses is to protect the vision, it has sought to establish a standard of quality. Currently there are three different standards:
– Australian Standard: AS 1067 is called, provides 5 levels of protection, ranging from 0 to 4.
– American Standard: The so-called ANSI Z80.3-2001, does not provide levels of protection, but requires certain levels of transmittance, which is the ability of energy that can penetrate a body in a certain time. The limits are established transmittance from 280 to 315 nm UVB and 315 to 380 nm in UV.
– European standard: EN 1836:2006 called, sets out five levels (0 to 4), where 0 and 1 are less protected, 2 and 3 are adapted to any situation and level 4 is recommended for extreme situations such as snow or water sports landscape. To identify the glasses respect this regulation, seek the CE logo.
Although the glasses were taken initially to certain terms are kept secret, to this day are necessary to protect eye health.