Why Cheap Sunglasses Are No Good
We here at HAWT have decided to take on your eye safety this summer of 2008 and explain to you why cheap sunglasses are just, simply, no good. Don't use 'em. Don't. Use. 'Em.
For the purpose of this post, we're gonna break down sunlight into two types of waves: visible light and ultraviolet light (UV). Of course visible light is the bright stuff that allows us to see things. You know, light. The other is UV, and it can do us some damage. UV is the main reason we get skin cancer, and people are wising up to this UV, checking the UV Index before heading out to the beach and correcting their sun protection accordingly.
Well, this UV also damages our eyeballs. It is the leading cause of welder's flash (photokeratitis or arc eye) and may lead to cataracts, macular degeneration, pterygium and pinguecula formations. None of those are fun. Let's look at all of this graphically, shall we? Here is the eye and sun on a normal day:
For the purpose of this post, we're gonna break down sunlight into two types of waves: visible light and ultraviolet light (UV). Of course visible light is the bright stuff that allows us to see things. You know, light. The other is UV, and it can do us some damage. UV is the main reason we get skin cancer, and people are wising up to this UV, checking the UV Index before heading out to the beach and correcting their sun protection accordingly.
Well, this UV also damages our eyeballs. It is the leading cause of welder's flash (photokeratitis or arc eye) and may lead to cataracts, macular degeneration, pterygium and pinguecula formations. None of those are fun. Let's look at all of this graphically, shall we? Here is the eye and sun on a normal day:
We're going to follow suit with scientist all over the world who replace a cow with a sphere to do calculations. We're replacing the eye with a box so you can see the parts of it. To the left of this box is the good ol' iris that expands and contracts to control how much light (and, therefore, UV) is allowed into the eye. To the right of this box is the retina, the back of the eye. Between the iris and retina would represent the inside of the eye. The more arrows in there, the more light and UV that's getting into the organ.
Again, the iris responds to its exposure to light, growing or shrinking accordingly.
Ok. The pieces are in place. We know UV exposure damages the eye. We know the iris responds to its environment. Now let's throw some cheap sunglasses in front of this eye, shall we? What happens? Well, on a bright day, the iris constricts and lets as little light in as possible.... with the cheap sunglasses, though?
Because the sunglasses cut down the light hitting the eye, the iris dilates, as if it were nighttime. Glass sunglasses, though, do nothing to stop UV rays, and so the dilated pupil acts like a wide-open floodgate for the bountiful UV rays. The cheap sunglasses, essentially, flood the eye with this UV radiation. That is noooooo good.
What is there to do? Well, that's why some sunglasses cost $10 and some cost $300. UV protection comes in the form of polarized lenses and UV coating. These expensive/protected lenses are usually made from plastic, and, according to HAWT, the ONLY lenses that should be in front of your ocular organs this summer.
UV protected and polarized lenses really do the trick. Of course, it's a little more complicated than that. Unlike my artistically directed lines, the light and UV from the sun come at your eyes from all angles. It bounces off the ground. It comes from straight above and to the side. Any angle is a good angle. So, if you wear little glasses that don't cover your entire eye, you're boosting that radiation in your eyeball. Any gap is a bad gap.
Bottom line: get UV protected, polarized lenses that are as big as possible. Yes, we at HAWT are recommending you look like this this summer.
Stay safe. Protect those eyes with the good stuff.
Ok. The pieces are in place. We know UV exposure damages the eye. We know the iris responds to its environment. Now let's throw some cheap sunglasses in front of this eye, shall we? What happens? Well, on a bright day, the iris constricts and lets as little light in as possible.... with the cheap sunglasses, though?
Because the sunglasses cut down the light hitting the eye, the iris dilates, as if it were nighttime. Glass sunglasses, though, do nothing to stop UV rays, and so the dilated pupil acts like a wide-open floodgate for the bountiful UV rays. The cheap sunglasses, essentially, flood the eye with this UV radiation. That is noooooo good.
What is there to do? Well, that's why some sunglasses cost $10 and some cost $300. UV protection comes in the form of polarized lenses and UV coating. These expensive/protected lenses are usually made from plastic, and, according to HAWT, the ONLY lenses that should be in front of your ocular organs this summer.
UV protected and polarized lenses really do the trick. Of course, it's a little more complicated than that. Unlike my artistically directed lines, the light and UV from the sun come at your eyes from all angles. It bounces off the ground. It comes from straight above and to the side. Any angle is a good angle. So, if you wear little glasses that don't cover your entire eye, you're boosting that radiation in your eyeball. Any gap is a bad gap.
Bottom line: get UV protected, polarized lenses that are as big as possible. Yes, we at HAWT are recommending you look like this this summer.
Stay safe. Protect those eyes with the good stuff.Join the HAWTaction reader group on Facebook.
I wear goggles at all times, even now while at the computer. Not only can light get in from all angles, but so can dust. Damn dust.
I'm the best blogger, ever.
- JLF
I'm with JLF - I wear my sunglasses at night...
Anyhoo, John: Will you buy me a new pair of Revos? Thanks buddy!
For you, Jason? Anything.
Thanks buddy. No need to go top of the line. A $200 pair will do fine.
Just make sure they are polarized and have UV coating!
That's a message from your mother here at HAWT.