You will need
- Two pairs of glasses, the device with LCD display
For safe driving, skiing and water sports, rest and work in bright environments need high-quality sunglasses. Regular dark lenses reduce the intensity of the radiation, thus worsening visibility, so they are not suitable for athletes and drivers and a stretch fit for ordinary people who want to protect from bright light the retina.
Polaroid glasses, in turn, differ from the usual that selectively block light beams. Imagine that the light propagating in three-dimensional space, extrapolated to a plane where there is only horizontal and vertical direction of the rays. If the vertical wavelength allow us to see the world in its parts and details, distinguish colors and outlines of objects, horizontal waves: reflections, lens flare, beams, directed into the eye, reducing susceptibility and prolonged exposure can damage the retina. Technology of polarized lenses to get rid of the direct sunlight, without reducing the detail of objects. For this reason, Polaroid sunglasses popular among drivers, sportsmen, fishermen, people with sensitive eyes.
Buy polarized glasses should be only in specialty stores, to protect yourself from counterfeiting. However, not all models produced by Polaroid, and other well-known manufacturers really equipped with suitable lenses. To check the polarization, special equipment required: enough points themselves, and any device with LCD display, for example, a mobile phone or a PC monitor.
Take the sunglasses, point them in the direction of the LCD monitor, and then expand to 45 ° vertically. As you turn you will notice how the image gradually darkens and disappears. If not, you are not dealing with the polarized lenses and ordinary colored glasses. Usually, this inexpensive model brands, however, possible fake or factory defect.
There is another way to check polarization of sunglasses. Ask the seller another pair with polarized lenses, attach points to each other and expand one pair relative to another rotated 90 degrees, so the lenses overlap each other. If both pairs of glasses made on the technology of Polaroid, the lumen will be dimmed. Conventional tinted glasses, nothing will happen.