The Science of Sunglasses: Understanding UV Protection and Lens Technology

From cat eye to aviator, sunglasses have become a fashion statement in their own right and can be found perched on the noses of everyone from style-conscious teens to the most idolised celebrities. Brands such as Dita have found their position in the eyewear industry by challenging the concept of functional eyewear and introducing strong fashion statements. 

While we agree that style shouldn’t be overlooked when it comes to choosing the perfect sunglasses, it’s important to remember that they do play an important role in maintaining eye health. Understanding this role and the science of sunglasses allows you to make the most informed decision this summer. 

How do sunglasses work? 

Much like the bill of a cap or a layer of sunscreen, sunglasses act as a physical barrier against direct sunlight. They block harmful UV rays and prevent them from penetrating through your eyes. Prolonged exposure to both UVA and UVB rays can cause damage to surface tissues, including those on your cornea and lens. UVA rays can reach the back of your eye, right to the retina and account for 95% of UV radiation. UVB rays on the other hand, only reach your cornea at the front of the eye but are the cause of painful sunburns. Both can have a significant impact on your eye health. By modifying the proteins in the eye, these rays impact your eye's ability to focus and can eventually lead to significant complications including cataract formation or cancers of the eye. 

Sunglasses step in to redirect and reflect these rays away from the eye's surface. Some of the most popular designs feature polarized lenses. These are laminated with a microscopic filter that runs in thin vertical strips and limits the amount of light that can pass through, preventing more than half of horizontal light from reaching your eye. Alongside these, you will also find several different sunglasses lenses that are all suited to specific activities but work similarly. For example: 

  • Gradient lenses have a darker tint at the top which gradually reduces as it moves down. This reduces the light’s transmission rate more significantly from above, making them ideally suited for environments with strong overhead sunlight.
  • Mirror-coated lenses have a reflective film that redirects excess light away while also reducing harsh glare. They are perfect for very bright conditions, which is why snow sports enthusiasts use them.
  • Photochromic lenses feature light-sensitive molecules that change in structure once they are exposed to UV rays. This darkens the lens and allows them to absorb more light, creating a protective barrier. 

Choosing the right sunglasses 

When you know how important sunglasses are, choosing the right pair should come down to more than just style. Consider where you plan to wear them and what activities have been organised. Think about how well-covered your eyes are with different styles and whether you need to opt for a coloured lens to improve visibility during wear. 

At The Eye Establishment, we provide professional support and guidance to help you identify the best style for you. Our range includes such iconic brands as Dita, which bring a discreetly luxurious range of ultra-comfortable glasses to your disposal - glasses that have long been coveted by celebrities worldwide. Dita prescription sunglasses and Dita prescription glasses allow you to experiment with style without compromising on eye health. 

Browse our online glasses shop here or visit our Kensington Opticians boutique to discover the perfect pair of Dita glasses to suit your needs today. If you need an eye examination then contact Eye Establishment. We have a variety of designer glasses and sunglasses that will suit your needs.