Sunglasses on the market are cheap by tens of yuan, or even a dozen yuan; expensive by a few hundred yuan or even higher. There is not much difference in appearance, why is the price so different?
In terms of price, regardless of the brand factor, it also depends on the quality of the material of the frame lens of the sunglasses, and whether the workmanship is fine and exquisite. For example, the frame is a common alloy, aluminum alloy or pure titanium material. The material of the lens is not UV-resistant, how many bands of UV-resistant, and no coating. These will determine the difference in production costs, and the retail price will naturally vary greatly.
Some people feel that it is enough to wear a pair of sunglasses to block the strong light and not dazzling, while some people feel that it is enough to wear them just for decoration.
The above idea is definitely wrong. It is better not to wear sunglasses with poor quality, but it will hurt the eyes even more.
Before explaining, let's talk about UV light. Ultraviolet rays are rays with a wavelength of 10-400 nm. Ultraviolet rays in nature mainly come from sunlight. The wavelength is 290-400nm. Long-term exposure to ultraviolet rays can cause mild dry eyes and visual fatigue; severe cases can lead to conjunctivitis, keratitis, uveitis, induced lens degeneration, cataracts, retinitis, and glaucoma.
After wearing the sunglasses, they will block the strong light, so that the eyes are darkened and not dazzling. But bright light is not UV rays, and inexpensive sunglasses offer little or no protection against UV rays. Under normal conditions, because the ozone layer in the atmosphere can filter and reduce ultraviolet rays, it will not endanger human health. The human eye in the dark environment, due to the physiological response, the pupil will be enlarged. After wearing such inferior sunglasses, the pupils become larger, the ultraviolet rays cannot be blocked, and a larger amount of ultraviolet rays enter the fundus, causing irreversible damage to the eyes. Therefore, from the perspective of health, although these sunglasses are cheap, it is better not to wear them.
Although high-quality sunglasses can also dilate the pupils, they can block the full range of ultraviolet rays and protect the health of the eyes. Furthermore, for low-priced sunglasses, in order to reduce the cost of design and production and assembly, all aspects of production are not up to standard. The face is curved, the curvature is unreasonable, the lens has a prismatic degree, the visual object is easily deformed, and there is an error in the color recognition.
Sunglasses are different from clothing or other accessories and affect their own health. So, don’t use cheap, low-quality sunglasses.