How to choose sunglasses
In the hot summer, are you troubled by the dazzling light that makes you unable to open your eyes? When we go on vacation at the seaside or ski in the snow, we all feel that the light is strong and dazzling, and we need sunglasses to protect our glasses. So are your sunglasses right?
When we buy sunglasses, we should observe whether the color of the object changes when we put on the glasses, whether the traffic lights are clear, and whether the design of the frame is suitable for us, whether there is dizziness after wearing, and stop wearing immediately if there is any discomfort. Generally, ordinary sunglasses only have the ability to block strong light and filter ultraviolet rays. For people with lower requirements, ordinary sunglasses can be used. However, some people who have higher requirements for visual quality will choose polarized glasses.
What are polarized glasses? According to the polarization principle of light, it can effectively exclude and filter the scattered light in the beam, so that the light can be put into the visual image of the eye from the light transmission axis of the right track, so that the field of vision is clear and natural, just like the principle of blinds, which naturally makes the scene look soft and not dazzling. . Polarized sunglasses have the effect of anti-ultraviolet rays, which can effectively isolate the harmful rays of the sun.
The first layer is a polarizing layer, which effectively absorbs the reflected glare perpendicular to the light transmission axis. The second and third layers are ultraviolet absorbing layers. It enables polarized lenses to absorb 99% of UV rays. So that the lamella is not easy to wear. The fourth and fifth layers are impact-resistant reinforcement layers. Provides good toughness, impact resistance, and protects eyes from injury. The sixth and seventh layers are strengthened, so that the layers are not easy to wear. The general polarized sunglasses on the market are made of fiber sandwiched polarizing film. It is different from optical glass polarized sunglasses, because of its soft texture and unstable arc, after the lens is assembled on the frame, the lens is difficult to meet the optical refractive standard, and the visual image is loose and deformed. Due to the instability of the arc and the deformation of the lens, it directly leads to poor clarity of the light-transmitting image and distortion of the image, which cannot achieve normal vision effects. And the surface is easy to be scratched, worn and not durable. Therefore, when purchasing polarized sunglasses, it is best to confirm that the lenses can effectively block more than 99% of ultraviolet rays (including ultraviolet A and ultraviolet B) and have both polarized characteristics to eliminate glare (glare refers to the strong light reflected from certain angles to the eyes. makes it difficult to see things temporarily).
The damage of ultraviolet rays to the human body is cumulative. The longer the exposure time in the sun, the greater the damage of ultraviolet rays. Therefore, we should wear sunglasses frequently to reduce the accumulation of ultraviolet rays in the eyes.
When choosing sunglasses, do not think that the darker the lens, the stronger the anti-ultraviolet effect. On the contrary, the darker the color, the bigger the pupil will become. Without safe anti-ultraviolet lenses, the eyes will be exposed to more ultraviolet rays, and the damage will be more severe. To avoid eye damage caused by ultraviolet rays, of course, it is necessary to minimize exposure to strong sunlight, especially between 10:00 a.m. and 2:00 p.m., when the sun shines directly on the surface of the earth, and the intensity of ultraviolet rays is the highest. Especially those ultraviolet rays reflected from concrete, snow, beach or water are the most powerful and cause the most damage to the eyes, but they are the most easily overlooked. Therefore, if you are going to be active in these places for a long time, remember to wear appropriate polarized sunglasses.
