When you go out on a sunny day and don’t protect your skin with sunscreen you suffer the consequences afterward. Having UV protection on sunglasses is like sunscreen for your eyes. This article talks about what UV rays are, how they can negatively affect your eyes and how you can prevent these damages.
What are Ultraviolet (UV) Rays?
Visible light occupies only a small portion of the electromagnetic spectrum. (Are you getting flashbacks of ROY-G-BIV?) There are other waves, of various wavelengths, that we cannot see with the naked eye. Some of these waves include x-rays, radio waves and, of course, UV rays. The wavelength of UV rays is shorter than the violet end of the visible spectrum but longer than the X-ray.
There are three different types of UV rays: UVA, UVB, and UVC. We will not be talking about UVC rays because it does not reach the earth’s surface since it is absorbed by the atmosphere.
- UVA: 95 percent of the UV radiation that reaches the earth’s surface is UVA rays.
- UVB: This type of UV radiation is more intense than UVA rays. The good thing is that the majority of UVB rays are filtered out by the ozone layer.
The shorter the wavelength, the more harmful the UV radiation. Thankfully, UVA has the longest wavelength of the three. It does, however, account for 95 percent of the UV radiation that reaches earth. It can penetrate into deeper layers of the skin and eye, compared to UVB. UVA can pass through the cornea and reach the lens and retina inside the eye. UVA rays are linked to long term damage, especially to skin aging and wrinkling. In the eye, it has been known to cause certain types of cataracts and also play a role in the development of macular degeneration. Refer to the section The Effects of UV Rays to learn more about these diseases.
UVB is of medium-wavelength compared to that of UVA and UVC. It only penetrates the superficial layers of the skin and eye, but it is more harmful than UVA rays. UVB is the wavelength that we’re all the most familiar with. This is because it causes more immediate effects -- sunburns. UVB is linked to the reddening and burning of the skin and even of the eyes (photokeratitis). It can also cause pingueculae and pterygia. Refer to the following section for further explanation about the effects of UV rays.
The Effects of UV Rays
Damage from UV rays is cumulative over a person’s lifetime. Unfortunately, we have yet to find a way to regenerate health in eyes like the health regeneration option in video games. It is especially important to wear sunglasses with UV protection if you live in a place that is sunny year round. However, UV rays can still penetrate clouds on an overcast day and reflect off of snow during winter months. This is why eye protection should be constant and start from an early age. Children are especially vulnerable to this since they are still growing and developing. A child with sunglasses is not only adorable, but it is also very beneficial for their eye health.
Some of the damages caused by extended UV exposure are as follows.
- Certain types of cataracts – a clouding of the lens that leads to a decrease in vision
- Pingueculae – yellow bumps on the white part of the eyes
- Macular degeneration – damage to the retina that causes loss of central vision
- Photokeratitis – sunburns on your eyes
- Pterygia – A growth on the clear tissue of the eye, also known as an eye web
Protection From UV Rays
It is important to check that the sunglasses you buy offer 99 or 100 percent protection from UVA and UVB rays. It is recommended to buy lenses that have a rating of UV400 or greater. What this means is that the lenses will block UV waves shorter than or equal to 400 nanometers (nm). The various ranges of UV rays are shown below.
UVA: 320-400 (nm)
UVB: 290-320 (nm)
UVC: 200-290 (nm)
This all might sound very expensive and you may not be willing to give up that much cash for a pair of sunglasses. But more money does not automatically equal more protection. Always check the label, read the description or ask a sales representative for more information about the UV protection. Avoid sketchy vendors or vague descriptions.
You can buy sunglasses with a UV coating, or many lens materials, such as polycarbonate lenses, have built-in UV coverage. All of our lenses here at Fuse have 100 percent UV protection, meaning they protect from all the types of UV rays, so you will never have to worry about that with us. A common misconception is that the darker the lenses, the more UV protection it offers. This is all false, clear lenses can also offer UV protection and some dark colored lenses might not offer any protection at all.
You might also consider photochromic lenses; these are lenses that start out clear and darken automatically in sunlight. Since it changes throughout the day, photochromic lenses give you, worry-free, all-day protection from UV rays.
For the best overall protection from the sun, polarized lenses are recommended. Although you can have sunglasses that are UV protected and not polarized, wearing polarized lenses help eliminate glare and reflections from the sun which makes your eyes less strained. All polarized lenses here at Fuse also offer UV protection. For a quick recap of how polarized sunglasses work, keep on reading.
What Are Polarized Sunglasses?
On particularly sunny days, sunlight has a tendency to bounce off of objects and blind you. Not only is it annoying, but it can also be potentially dangerous. When you wear polarized sunglasses, this glare is blocked out because of the polarization of light waves. Since light travels in all directions, polarized lenses filter it by only letting the verticle light waves through. The reason this works is that when sunlight produces a glare it is horizontal and it cannot pass through the vertical filtration. This is all done thanks to a special chemical coating on the lenses.
Why Wear Polarized Sunglasses?
The main reason to wear polarized sunglasses is to help block the sun’s glare when it reflects off things like calm waters and cars. When the sunlight bounces off, it can hinder your vision and cause you to squint. The polarization of the lenses can also help with improving color contrast, reducing eye strain and seeing into the water.
That is why people who do activities like fishing, boating, hiking, running, skiing, biking, and driving can greatly benefit from wearing polarized sunglasses. In the article “What are the benefits of polarized sunglasses?”, there is more information about the process of polarizing light and the benefits of using polarized lenses.
- In the electromagnetic spectrum ultraviolet (UV) rays is located after the violet end of the visible part of the spectrum but before X-ray. (In a diagram where the wavelength is going from long to short). UV rays are invisible to the naked eye.
- There are three different types of UV radiation: UVA, UVB, and UVC. The earth’s atmosphere prevents UVC from reaching the surface.
- UVA is the most prevalent, 95 percent, and can penetrate into deeper layers of the eye, compared to UVB.
- The majority of UVB rays are filtered out by the ozone layer, but the few that do reach the surface are more dangerous than UVA. As a rule of thumb, the shorter the wavelength, the more harmful the UV radiation.
- Damages from UV rays are cumulative. Despite the time of year or the weather outside, it is important to protect your eyes. Children are especially vulnerable to UV exposure, so the sooner you start protecting your eyes, the better.
- Many eye health issues including cataracts, pingueculae, macular degeneration photokeratitis, and pterygia can develop with exposure to UV radiation.
- For best UV protection it is recommended to buy lenses that have a rating of UV400 or greater. You have the option of buying lenses with a UV coating or lenses that have built-in UV coverage. Other recommendations are photochromic lenses, lenses that transition from clear to dark, and polarized lenses.
- Polarized lenses filter out sun glares that bounces off objects by only allowing verticle light waves through.
- Polarized sunglasses not only help with reducing glare but also improving color contrast, reducing eye strain and being able to see into the water. That is why it is helpful when performing outdoor activities like fishing, boating, running, hiking, skiing, biking, and driving.
Stop procrastinating when it comes to protecting your eyes! Shop our lenses at Fuse Lenses and soak up the sun with no worries because all of our glasses have UV protection.