Eye Health Central

What Is UV 400 Protection On Sunglasses?

UV 400 Protection Explained

Sunglasses with UV 400 protection

It’s easy to get caught up in only caring about what your sunglasses look like and forget the real reason why we need sunglasses, which is to protect our eyes against harmful UV rays! Understanding the terminology surrounding UV protection is not essential, but understanding the importance of UV protection will mean you are much more likely to ensure your sunglasses have it, and to wear them more often. It could be said that your sunglasses are just mini, stylish, shields for your eyes… so here’s everything you need to know about ‘UV 400 protection’ and why your "mini shields" should have this!

Defining UV 400 Protection:

UV 400 protection refers to a specific level of ultraviolet radiation blocking capability in sunglasses. It's not just a marketing gimmick; it's an industry standard that ensures your eyes are shielded from both UVA and UVB rays, which are harmful components of the sun's UV spectrum. The "UV" in UV 400 stands for ultraviolet, and the "400" indicates the wavelength at which the protection stops – 400 nanometres, it also guarantees the glasses will provide almost 100% protection from UV rays up to 400 nanometers which include UVA and UVB.

Understanding UVA and UVB Rays:

UVA (long-wave) and UVB (short-wave) rays are part of the sun's radiation that reaches the Earth's surface. UV protection sunglasses are categorised based on their ability to block out UV radiation. The two main categories are:

  • UV-A Protection: These sunglasses block UV-A rays, which have longer wavelengths and can penetrate deeper into the eye. UV-A rays are associated with skin ageing, and prolonged exposure can contribute to cataracts and macular degeneration.
  • UV-B Protection: These sunglasses block UV-B rays, which have shorter wavelengths and are primarily responsible for causing sunburn, as well as contributing to the development of cataracts and skin cancer around the eyes.

Both types of rays, if absorbed by the eyes over an extended period, can lead to serious eye health issues, photokeratitis including cataracts, macular degeneration, and even some forms of eye cancer.

It's crucial to opt for sunglasses that offer both UV-A and UV-B protection to ensure comprehensive defence against the harmful effects of UV radiation.

The Importance of UV 400 Protection:

Wearing sunglasses with UV 400 protection offers a range of benefits that go beyond just looking stylish. Here's why it matters:

  • Eye Health: Prolonged exposure to UVA and UVB rays can harm your eyes. UV 400 protection ensures that your sunglasses block at least 99.9% of these harmful rays, reducing the risk of eye damage.
  • Reduced Risk of Eye Conditions: By shielding your eyes from UV radiation, you're lowering the likelihood of developing cataracts, macular degeneration, and other eye conditions linked to UV exposure.
  • Prevention of Photokeratitis: UV 400 protection also guards against photokeratitis, often referred to as "snow blindness" This painful condition is akin to sunburn on the cornea and can cause temporary vision loss.
  • Long-Term Vision Preservation: Investing in UV 400-protected sunglasses is an investment in your long-term eye health. By protecting your eyes today, you're taking steps to maintain clear vision well into the future.

Types of UV Sunglasses:

UV protection sunglasses come in various styles, materials, and lens technologies to suit different preferences and needs. Some popular types include:

  • Wrap-around Sunglasses: These sunglasses have lenses that curve around the sides of your face, providing extra protection by minimising the amount of UV rays that can reach your eyes from the sides.
  • Polarised Sunglasses: Polarised lenses not only block UV rays but also reduce glare from reflective surfaces like water, snow, and roads. This makes them ideal for outdoor activities like boating, skiing, and driving.
  • Photochromic Sunglasses: Also known as transition lenses, these sunglasses darken in response to UV light, adapting to changing light conditions. They provide UV protection indoors and outdoors.
  • Mirrored Sunglasses: Mirrored coatings on the lenses help to reflect light away, providing an additional layer of protection against glare and intense sunlight.
  • Gradient Sunglasses: These sunglasses have lenses that are darker at the top and gradually become lighter toward the bottom. They are suitable for activities where you need to see clearly both at a distance (through the darker portion) and up close (through the lighter portion).
  • Sports Sunglasses: Designed for specific activities, such as cycling, running, or golf, these sunglasses often feature shatter-resistant lenses and secure fit designs to stay put during movement.

Selecting Reliable UV 400 Sunglasses:

While many sunglasses claim UV protection, not all of them offer the same level of defense. To ensure you're getting reliable UV 400 protection, keep these points in mind:

  • Check the Label: Look for sunglasses that are labeled as providing "100% UV 400 protection" or "blocks 100% of UVA and UVB rays." This labeling indicates that the sunglasses meet the necessary standards.
  • Buy from Reputable Brands: Opt for sunglasses from reputable brands or stores that prioritise eye health and safety. Established brands are more likely to adhere to quality standards.
  • Visit an Optometrist: If you're unsure about the quality of your sunglasses, consider visiting an optometrist. They can test the sunglasses to verify their UV protection capabilities.
  • Fit: The sunglasses should fit comfortably on your face, covering your eyes and the surrounding areas. Proper fit ensures maximum protection.
  • Activity: Consider the activities you'll be engaging in while wearing the sunglasses. Certain sports may require specialised designs for optimal protection and performance.

It’s crucial that you understand the level of protection that your sunglasses provide for you… if you have a pair of sunnies that look great AND protect your eyes you’re doing great (and shouldn’t settle for less than that!). when shopping for your next pair of sunglasses, ensure you only look for those with UV protection to protect your eyes as much as possible.

It's advised to carry out a little research before purchasing those beautiful on-trend sunnies you've been after, make sure the website is legit with good customer aftercare and great reviews, While there, check out some of those reviews they really can help you make up your mind.
If the sun is out and you think you may need sunscreen then you definitely need to be wearing your UV 400 protection sunglasses

Happy sunglasses shopping! 

Author: John Dreyer Optometrist Bsc(Hons), MCOPTOM, DipCLP
Created: 22 Sep 2023, Last modified: 20 May 2024