Sunglasses Basic Functions
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Wearing the wrong Sunglasses could damage your eyes!
A pair of sunglasses may seem simple: two colored glass or plastic lenses enclosed in a plastic or metal frame. In reality, the two glass lenses can produce a wide range of differences, and these differences can have a significant impact on how people use them.
Effects
Ultraviolet rays can damage the cornea and retina, but high-quality sunglasses completely eliminate them.
When the eye receives too much light, it naturally constricts the iris. Once the iris constricts to its limit, people need to squint. If there's still too much light, such as sunlight reflected off snow, it can damage the retina. High-quality sunglasses can filter out up to 97% of incoming light to prevent damage.
Some surfaces, such as water, reflect a large amount of light, creating bright spots that can disrupt vision or obscure objects. High-quality sunglasses can completely eliminate this glare using polarization technology, which we'll discuss later.
Some frequencies of light blur vision, while others enhance contrast. Choosing the right color for your sunglasses can optimize performance in specific conditions. If sunglasses don't provide UV protection, they increase exposure to UV rays. Cheap sunglasses filter out some light, causing the iris to dilate to receive more light. This also allows more UV rays to enter, increasing the damage to the retina.
Therefore, there are indeed differences between different types of sunglasses. Choosing the right, high-quality sunglasses for specific usage conditions will provide the best protection.
According to international standards, sunglasses are classified as personal eye protection products. Their primary function is to block glare from the sun. However, international standards further subdivide sunglasses into "fashion glasses" and "general-purpose glasses." The standards have lower quality requirements for "fashion glasses" because they primarily emphasize style, and wearers prioritize aesthetics over protection. The standards for "general-purpose glasses" are more stringent, including requirements for UV protection, as well as diopter and prism power.
