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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 8 of 8. This is the beginning of the thread.
Posted by saturn on April 29, 2006, at 20:13:45
I've posted questions on this before, but thought I'd bring it up again.
Does car window-tinting block UVA and/or UVB light?
In other words will it protect your skin and eyes?
Posted by MidnightBlue on April 29, 2006, at 21:14:28
In reply to tinted windows, posted by saturn on April 29, 2006, at 20:13:45
From what I have heard/read, the answer is no it will not protect your skin or eyes. Not sure if it is UVA or UVB or both that come through though.
> I've posted questions on this before, but thought I'd bring it up again.
>
> Does car window-tinting block UVA and/or UVB light?
>
> In other words will it protect your skin and eyes?
Posted by saturn on May 1, 2006, at 22:13:57
In reply to Re: tinted windows, posted by MidnightBlue on April 29, 2006, at 21:14:28
> From what I have heard/read, the answer is no it will not protect your skin or eyes. Not sure if it is UVA or UVB or both that come through though.
Thanks Midnight Blue (nice name btw).
What I could come up w/ is there are three types of UV light: UVA, UVB, UVC. UVC is the most powerful and dangerous, but does not enter our atmosphere (ozone protection? not sure). Both UVA and UVB cause eye and skin damage, but not equally. UVB does not penetrate glass (less than 1%). However, UVA does unless special coating is applied (not necessarily just a dark "tint")---and this coating does not need to be dark---it can be transparent. This is what I've been able to come up with, and I think the facts are accurate, but I could be mistaken.
I am a vampire and so burn in m'car in the summer and need some serious protection from the sunlight.
Posted by Larry Hoover on May 7, 2006, at 16:36:52
In reply to tinted windows, posted by saturn on April 29, 2006, at 20:13:45
> I've posted questions on this before, but thought I'd bring it up again.
>
> Does car window-tinting block UVA and/or UVB light?
>
> In other words will it protect your skin and eyes?Automotive safety glass blocks essentially all UVB, and the shorter UVA (higher energy) bands (less than 10% transmission), up to about 390 nm wavelength. The bands of UVA with nearly complete transmittance are roughly analogous in energy to the bulbs that people call black lights, the psychedelic poster thing.
There is always the possibilitity that a higher energy photon in the UVB band just happens to fail to strike an atom in the glass its trying to pass through. Photon transmission goes to zero, but may not be zero, in the UVB band. Thicker glass transmits less than thin. As you slide up into the UVA, % transmittance increases, but quite gradually, at first.
You can still get a sunburn behind auto glass, but it would take a lot longer than you would have required in direct sunlight. A lot longer.
If you can see the tint on a piece of glass, then bands in the visible wavelengths are involved, and that may or may not correspond to ultraviolet bands being similarly influenced. The UV protective coating that is put on sunglasses happens to be transparent in the visible range, i.e. it is clear and colourless. But it is opaque at ultraviolet frequencies. They are distinct properties.
Lar
Posted by saturn on May 8, 2006, at 7:13:11
In reply to Re: tinted windows » saturn, posted by Larry Hoover on May 7, 2006, at 16:36:52
> > I've posted questions on this before, but thought I'd bring it up again.
> >
> > Does car window-tinting block UVA and/or UVB light?
> >
> > In other words will it protect your skin and eyes?
>
> Automotive safety glass blocks essentially all UVB, and the shorter UVA (higher energy) bands (less than 10% transmission), up to about 390 nm wavelength. The bands of UVA with nearly complete transmittance are roughly analogous in energy to the bulbs that people call black lights, the psychedelic poster thing.
>
> There is always the possibilitity that a higher energy photon in the UVB band just happens to fail to strike an atom in the glass its trying to pass through. Photon transmission goes to zero, but may not be zero, in the UVB band. Thicker glass transmits less than thin. As you slide up into the UVA, % transmittance increases, but quite gradually, at first.
>
> You can still get a sunburn behind auto glass, but it would take a lot longer than you would have required in direct sunlight. A lot longer.
>
> If you can see the tint on a piece of glass, then bands in the visible wavelengths are involved, and that may or may not correspond to ultraviolet bands being similarly influenced. The UV protective coating that is put on sunglasses happens to be transparent in the visible range, i.e. it is clear and colourless. But it is opaque at ultraviolet frequencies. They are distinct properties.
>
> Lar
>
Thanks Lar,I really appreciate the info. Can't imagine where else I'd find all that out. Guess I'll just be driving with my windows up this summer. Take care,
-sat
Posted by Larry Hoover on May 8, 2006, at 9:09:56
In reply to Re: tinted windows » Larry Hoover, posted by saturn on May 8, 2006, at 7:13:11
> I really appreciate the info. Can't imagine where else I'd find all that out. Guess I'll just be driving with my windows up this summer. Take care,
>
> -satYou're most welcome. Just remember to ask your questions when I'm not blocked. <wink>
Lar
Posted by saturn on May 8, 2006, at 15:33:10
In reply to Re: tinted windows » saturn, posted by Larry Hoover on May 8, 2006, at 9:09:56
> Just remember to ask your questions when I'm not blocked. <wink>
>
> LarGotcha Lar (<wink back>) ;)
Since you're so knowledgeable on the physics of this stuff, do you know if blue spectrum light (responsible for circadian rhythms) passes through glass?
peace
>
Posted by Larry Hoover on May 8, 2006, at 16:56:41
In reply to Re: tinted windows » Larry Hoover, posted by saturn on May 8, 2006, at 15:33:10
> Since you're so knowledgeable on the physics of this stuff, do you know if blue spectrum light (responsible for circadian rhythms) passes through glass?
>
> peaceOrdinarily, it does.
Lar
This is the end of the thread.
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