Q: Test Sunglass UV Protection

[Mike Monett]

Summer is upon us, and maybe last year's sunglasses are lost or too
scratched to use. It's time to get new ones.

UV protection is becoming more important as we learn more about the
damage it causes to the eyes. For example, dark glasses cause the iris
to open, which allows more UV radiation to enter the eye. If the
sunglass passes UV radiation, they may do more harm than good.

The "UV 400" industry standard turns out to be voluntary, with large
variations in performance among eyeglass manufacturers. Since we
cannot see UV, some kind of photospectrometer is needed to test the
transmission characteristics of sunglasses. But photospectrometers are
expensive and not usually available to everyone.

With the concerns about UV damage to the eyes, can anyone think of a
simple way to test the ultraviolet protection of different sunglasses?

One thing to keep in mind is the transmission characteristics of some
films may not be uniform and may have sharp peaks. Assuming worst case
damage effects, these should be included in the test.

Any guesses?

Regards,

Mike

 

[Paul Hovnanian P.E.]

Mike Monett wrote:

Summer is upon us, and maybe last year's sunglasses are lost or too
scratched to use. It's time to get new ones.

UV protection is becoming more important as we learn more about the
damage it causes to the eyes. For example, dark glasses cause the iris
to open, which allows more UV radiation to enter the eye. If the
sunglass passes UV radiation, they may do more harm than good.

The "UV 400" industry standard turns out to be voluntary, with large
variations in performance among eyeglass manufacturers. Since we
cannot see UV, some kind of photospectrometer is needed to test the
transmission characteristics of sunglasses. But photospectrometers are
expensive and not usually available to everyone.

With the concerns about UV damage to the eyes, can anyone think of a
simple way to test the ultraviolet protection of different sunglasses?

One thing to keep in mind is the transmission characteristics of some
films may not be uniform and may have sharp peaks. Assuming worst case
damage effects, these should be included in the test.

Any guesses?

I don't know if it meets any FDA or other medical standards, but my
optometrist has a test set for determining UV, IR and visible light
attenuation. I have no idea if its calibrated or measures the correct UV
bands. It is used for comparing various brands of sunglasses, tinted
coatings, etc. It could be nothing more than a sales gimmick, but if a
little care was put into the device, it could give useable results.

--
Paul Hovnanian mailtoaul@Hovnanian.com
note to spammers: a Washington State resident
------------------------------------------------------------------
Where am I going, and what am I doing in this handbasket?

 

[Mike Monett]

Paul Hovnanian P.E. wrote:

[...]

I don't know if it meets any FDA or other medical standards, but my
optometrist has a test set for determining UV, IR and visible light
attenuation. I have no idea if its calibrated or measures the correct UV
bands. It is used for comparing various brands of sunglasses, tinted
coatings, etc. It could be nothing more than a sales gimmick, but if a
little care was put into the device, it could give useable results.

Paul Hovnanian mailtoaul@Hovnanian.com
note to spammers: a Washington State resident
------------------------------------------------------------------
Where am I going, and what am I doing in this handbasket?

Interesting - thanks for the reply. Any idea of the make and model of this
device? Could you call him and ask? If we can find information on how it
works, it might be possible to make a simple and inexpensive version.

I'll call some optometrists in this area and see if anyone has one.

Regards,

Mike Monett