Brenda, indeed, what I say is true. You see, lenses from companies
such as Oakley, Smith, Bolle, Ray Ban, Costa Del Mar, etc. are
actually engineered to reduce eye strain, even if you are unable to
detect it consciously.
Lenses from cheep Chinese companies have no effort put into reducing
eye strain, instead, they make them to look cool and make everything
look like night when tried on at Wally World. They also slap on that
90%+ UV protection sticker that is actually false advertising.
Here are some sources.
http://www.ganoksin.com/gnkurl/ep80gg
http://www.ganoksin.com/gnkurl/ep80gh
http://www.ganoksin.com/gnkurl/ep80gi
Speaking from experience here; I used to wear cheep sunglasses when
I was younger and experienced severe headaches on a regular bases
when exposed to the sun for extended periods. This all changed when I
made the switch to Wiley X and then later Oakley (which is the better
company in my opinion).
Now, I realize we as jewelers are not sitting behind a torch for
hours on end (most of us anyway) but keep in mind the cumulative
effect - over a decade or two the damage can really add up.
Here’s a technical article for the geeks:
Essentially the low down is oxyacetylene torches very commonly used
for industrial welding and jewelry manufacturing produce a large
quantity of high energy short wavelength light, most commonly known
as the UV spectrum, that is very harmful to the retinas; the same
light (but less concentrated) that our eyes are exposed to when
outdoors.
By way of disclaimer: I am in no way affiliated with the companies
mentioned.
Kaleb