How Sunglasses Block Harmful UV Rays
Have you ever wondered what's happening behind those lenses when you slip on a pair of sunglasses? Those sleek shades aren't just an accessory - they're actually your eye health's best friend. Get ready to gain a new appreciation for the science and technology built into the humble pair of sunglasses. We'll break down how different lenses filter light, what those UV protection ratings really mean, and why opting for polarization is worth it. You'll learn exactly how sunglasses work their magic to fend off glare and keep your peepers in tip-top shape. Who knew there was so much more to shades than just looking cool? By the end, you'll be seeing sunglasses in a whole new light.
Different Lens Types: Polarized, Mirrored, and More
UV radiation from the sun comes in two forms: UVA and UVB rays. Sunglasses block UV rays from reaching your eyes using special lenses and materials that absorb or reflect the light.
Polarized lenses block intense reflected light, reducing glare. Mirrored lenses have a reflective coating that deflects light. Both lens types offer UV protection in stylish shades. For the best protection, look for sunglasses that block 100% of UVA and UVB rays.
In the U.S., sunglasses are rated using a UV protection rating system. To be considered UV-protective, sunglasses must block at least 95% of UVB rays and at least 60% of UVA rays. The higher the rating, the better. UV400, for example, blocks 100% of UV rays.
If you wear prescription glasses, you can get prescription sunglasses. Your eye doctor can make sunglasses with your prescription in the lens and the same UV protection as regular sunglasses. Transitions lenses that darken in sunlight also provide UV protection.
Sunglasses do more than make you look cool. They protect your eyesight and long-term eye health. UV exposure over time causes damage to the retina, cornea, lens and other eye tissues. It can lead to cataracts, macular degeneration, and other issues. Sunglasses, especially those with maximum UV protection, help prevent damage and reduce your risks of vision problems from sun exposure.
Wearing quality sunglasses, especially in the middle of the day when the sun is strongest, is one of the best things you can do for your eye health and to maintain good eyesight for years to come. Your eyes will thank you!
The Benefits of Polarized Sunglasses
Sunglasses come with all kinds of lenses, each designed for specific purposes. Polarized lenses block intense reflected light and glare, perfect for driving or being out on the water. Mirrored lenses have a reflective coating that reduces the amount of light passing through the lens. They’re great for hiding your eyes from others!
Polarized Lenses
Polarized lenses contain a special polarized filter that helps block intense reflected light, like glare from water or snow. They’re ideal for driving, boating, fishing, or any other activity where glare reduction is important. Polarized lenses also help improve contrast and visibility. The downside is that some electronic displays like LCD screens can appear distorted or darker when viewed through polarized lenses.
Mirrored Lenses
Mirrored lenses have an ultra-reflective metallic coating, usually silver, gold or rose gold in color. They reduce the amount of light passing through the lens by reflecting much of it away. Mirrored lenses are popular for their stylish appearance but also help hide your eyes from view. However, the mirror coating can scratch over time and in some cases peel or flake off. Mirrored lenses also typically don’t offer polarization, so they won’t reduce glare.
Photochromic or Transitional Lenses
If you need prescription glasses, you can get sunglasses with photochromic lenses that darken in sunlight and lighten in low light or indoors. Transitional lenses contain special light-sensitive molecules that cause the lens to darken when exposed to UV radiation. The more UV exposure, the darker the lens becomes. When UV levels decrease, the lens transitions back to a clear state. Transitional lenses are very convenient but can take some time to fully darken and lighten.
With so many lens options, you can find the perfect pair of shades for any occasion or activity. Just be sure to look for impact-resistant lenses with 100% UV protection to keep your eyes healthy and safe from the sun.
Understanding UV Protection Ratings
Block Harmful Rays
Polarized lenses dramatically reduce glare from reflective surfaces like water, snow, and roads. The polarizing filter aligns the light waves entering the lens so that only light waves that are vibrating in a vertical direction can get through. This cuts out the excess scattered light and reduces squinting when outside in bright conditions. Without this excess light, you'll notice colors seem more vivid and true. Polarized lenses are especially useful for driving, boating, skiing, and other outdoor activities.
More Comfortable Vision
By filtering out intense reflected light, polarized sunglasses make it more comfortable for your eyes to focus and see details. They help prevent eyestrain from the sun's glare and allow you to see into water or snow. This makes them ideal for fishing or watersports where spotting fish or obstacles just under the surface is important. The reduced glare also makes polarized lenses safer for driving, as you have a clearer view of the road.
Protect Your Eyes
Like regular sunglasses, polarized lenses also block 100% of UVA and UVB rays to protect your eyes from sun damage. Prolonged sun exposure can lead to conditions like cataracts, macular degeneration, and skin cancer around the eyelids. Polarized lenses rated UV400, like most quality sunglasses, block both UVA and UVB radiation for full protection.
Stylish and Sporty
Polarized sunglasses come in a variety of fashionable styles for everyday casual wear as well as sporty wraparound designs for outdoor activities. Popular brands like Ray-Ban, Oakley, and Costa Del Mar offer polarized versions of their classic aviator and wayfarer styles as well as performance sport sunglasses. So in addition to the functional benefits, you can choose polarized lenses in frames that match your style and needs.
Prescription Sunglasses: Custom Shades for Your Eyes
When buying sunglasses, it’s important to understand UV protection ratings to ensure your eyes stay healthy. The UV rating, or UV protection factor (UPF), indicates how much UV radiation is absorbed by the lens. The higher the rating, the more UV rays are blocked.
UVA and UVB Rays
The two types of harmful UV rays are UVA and UVB. UVA rays penetrate deep into the skin and eyes, while UVB rays burn the superficial layers. Look for sunglasses that block 100% of both UVA and UVB rays.
UV 400 Rating
An UV 400 rating means the lenses block at least 99% of UV rays up to 400nm, including UVA and UVB. This is a very high level of protection and what you should aim for. Lesser ratings like UV 200 or 300 still allow a percentage of UV radiation to reach your eyes.
Polarization and Photochromic Lenses
Polarized lenses reduce glare and reflective light, making them great for driving or water activities. Photochromic lenses darken in sunlight and lighten in low light, conveniently adjusting to conditions. While convenient, these lens types alone may not offer full UV protection. Look for ones specifically rated UV 400 as well.
ANSI and UV Standards
Reputable brands will have their sunglasses tested and rated according to official standards. In the U.S., sunglasses should meet ANSI Z80.3 standards and be UV 400 rated. In Australia/New Zealand, look for the UV Protection Category 4 rating. For the EU, sunglasses should be rated UV 400 and CE marked.
The level of UV protection can vary between lens types, brands and price points. When buying sunglasses, check the product specifications to ensure maximum UVA/UVB coverage and UV 400 rating. Your eye health depends on it! Protecting your eyes from UV damage will help prevent conditions like cataracts, age-related macular degeneration, and other issues. Take the time to understand UV ratings and choose sunglasses that block 100% of UV rays. Your eyes will thank you!