Why You Should Replace Your Sunglasses Every 2 Years

As the scorching summer sun persists, many of us turn to sunglasses to protect our skin and eyes from harmful rays. But have you ever considered the "expiry date" of your sunglasses? A recent study reveals that the lifespan of a pair of sunglasses is about two years, after which they may lose their ability to protect your eyes.

According to researchers from the University of São Paulo in Brazil, prolonged exposure to sunlight can reduce the UV-blocking capability of sunglasses. Over time, if not replaced, sunglasses can lead to damage to the cornea and other vision problems. The study indicates that exposure to the sun can cause sunglasses to degrade, making the lenses lighter and reducing their resistance to impact — in other words, their anti-shatter performance.

The World Health Organization (WHO) has highlighted the significant risks of UV radiation, noting that 5% of the 18 million people worldwide who go blind each year due to cataracts are affected by UV exposure. UV rays can also cause other severe eye conditions, including corneal inflammation, retinal damage, cataracts, macular degeneration, and snow blindness. Therefore, UV-blocking sunglasses are essential for protecting our eyes under the sun.

In a series of experiments conducted across Europe, Australia, New Zealand, and South America, researchers simulated sunlight exposure by placing sunglasses under a UV light simulator, 30 cm away from the light source for 50 hours, observing the degradation of their UV-blocking capabilities.

The results showed that sunglasses degrade faster in tropical regions, where UV levels are highest. The study notes that the degradation of sunglasses varies with latitude, and in tropical regions, the UV index remains high in summer and winter.

Researchers recommend replacing sunglasses after two years of use to ensure they continue to provide effective protection.

Finally, remember to choose the right sunglasses for your needs and replace them regularly. Don’t let outdated sunglasses become an invisible threat to your eyes.