Share The sun is responsible for up to 90% of visible signs of aging. While all cells age naturally, exposure to ultra-violet (UV) light increases the rate at which skin aging occurs . Ultra-violet light degrades the self-renewing capability of the skin, which can prevent it from blocking harmful substances from getting into your body . Additionally, prolonged sun exposure can negatively impact collagen and elastin production making the skin lose structure and firmness. Photo-aging also impacts wound repair, pigmentation, and subcutaneous fat production . The overall result is skin that is more prone to wrinkles, dark spots, sagging, and is less effective at protecting from external stressors and recovering from disease . For healthy, resilient skin at all ages, it’s important to be mindful of UV light exposure. That’s why it is recommended that wearing sunscreen should be a daily practice. Go Beyond The Bottle While sunscreens are extremely helpful in limiting the amount of UVA and UVB light to which your skin is exposed, there is always a small amount of sun it cannot block. The SPF value, or Sun Protection Factor, tells you how long the sun’s radiation would take to redden your skin when using that product compared to the time without sunscreen. So, while SPF 30 blocks 97% of the sun’s rays, there’s always that 3% exposure. Light-exposure is cumulative so every bit of protection counts! When it comes to having the best, healthiest possible skin, practice safe sun by wearing sunscreen with at least SPF 30 and when you can, wear protective clothing, add a sun hat, and try hanging out in the shade. Reference  Rittié, L., & Fisher, G. J. (2015). Natural and sun-induced aging of human skin. Cold spring harbor perspectives in medicine, 5(1), a015370.