preface
A pair of sunglasses looks very simple, which means there are two colored glass or plastic sheets inside a certain plastic or metal frame. Is there anything simpler than this? In fact, two glass lenses can create many differences, and these differences can also have a significant impact on you when using sunglasses.
effect
Ultraviolet rays can damage the cornea and retina, and high-quality sunglasses can completely eliminate ultraviolet radiation.
When the eye receives too much light, it naturally contracts the iris. Once the iris contracts to its limit, people then need to squint. If there is still too much light, such as the sunlight reflected by snow, it will cause damage to the retina. High quality sunglasses can filter out up to 97% of the incoming light to avoid injury.
Some surfaces, such as water surfaces, can reflect a large amount of light, and the resulting bright spots can disrupt vision or hide objects. High quality sunglasses can completely eliminate such glare using polarizing technology, which we will introduce later.
Some frequencies of light can blur the line of sight, while others can enhance contrast. Choose the correct color for sunglasses to achieve better results in specific environments.
If sunglasses do not provide UV protection, they will expose you more to UV radiation. Cheap sunglasses filter out some of the light, causing your iris to open to receive more light. This also allows more ultraviolet rays to enter, increasing the damage that ultraviolet rays cause to the retina.
Therefore, there are indeed differences between various types of sunglasses. Choosing suitable and high-quality sunglasses for a specific usage environment will provide you with the greatest protection.
According to international standards, sunglasses are classified as personal eye protection products. The main function of sunglasses is to block out harsh sunlight. However, international standards further subdivide sunglasses into "fashion mirrors" and "general purpose mirrors". The quality requirements for "fashion mirrors" in the standard are relatively low. Because "fashion mirrors" mainly highlight style, the wearer focuses on decoration rather than protective functions. The quality requirements for general purpose mirrors in the standard are relatively strict, including requirements for UV protection, refractive index, and prism index.