Why You Should NEVER Buy Cheap Glasses

So recently, I bought the cheapest pair of glasses I could find on ebay with free shipping, to see if they were good.:thinking:

Safety Glasses 600nm 700nm Red Laser Protection Goggle with Hard Protect Box Hot | eBay

I got them today and tested them. Absolutely horrible. :scowl:
Here are some pics I took while testing them. BTW, I used a 650nm 300mw build as the laser.
philipd7's Library | Photobucket

If I were not told one of the pictures has glasses over them, and not just some filter, I would not notice a difference.
So, please just pay the extra money to get good glasses.:wave:
Good Glasses: Safety Goggles

Remember, your vision is priceless.

I have a feeling this is especially common with the blue glasses that are supposed to block the red as a couple of other people have posted something like this in the past.

I would also advise against the "Trex" blue glasses, I think they are $20 or less on Amazon although they do block much red and are very dark I wouldn't trust them to protect me from a direct hit from a 100mW red laser.

Alan

True like PI. said, I got what looks like the exact same pair from fastech and they do absolutely nothing. I paid $9 though. Could it really be that much more to darken the tint?

those blue glasses only seem to work with 635nm.

SyKo said:

those blue glasses only seem to work with 635nm.

Click to expand...

That's too bad because most beginners get 650nm lasers, then go and buy these glasses.

yep, i wouldve gotten a pair of those a little more than 3 years ago and upon using them was immediately thinking ' This bright red dot is still bright...' wasnt until recently i tried them with a ~30mW 635nm and it seemed to do its job perfectly, nothing but a faint red circle.

SyKo said:

yep, i wouldve gotten a pair of those a little more than 3 years ago and upon using them was immediately thinking ' This bright red dot is still bright...' wasnt until recently i tried them with a ~30mW 635nm and it seemed to do its job perfectly, nothing but a faint red circle.

Click to expand...

I find it hard that 15nm or actually 12nm if they rate these reds at 638nm can make such a difference but stranger things have happened. I waited 3 1/2 weeks for delivery to find out in 5 seconds these glasses were garbage. This was the only time I was dissapointed with fastech as they refused a refund or credit because they said the glasses came unbroken. Even for the sake of it I tried them to see if the worked like sun glasses or at least helped. "Hey I wanted them to do something at this point". Not even a thing

That would be really frustrating

Isn't it funny how specific these generic glasses are with their wavelength compatibility...?

I don't go for online shopping. I had almost the same experience. Once I bought a wrist watch online. The first day was okay. Second day onwards time just stopped. I tried to repair it, but it was of no use. Just waste of money.

Hilda200 said:

I don't go for online shopping. I had almost the same experience. Once I bought a wrist watch online. The first day was okay. Second day onwards time just stopped. I tried to repair it, but it was of no use. Just waste of money.

Click to expand...

Usually the problem is more of a "buy cheap, pay twice thing". Not much to do with shopping online. You can get great quality stuff that works and lasts online just fine, you just need to spend the cash and do the research.

You may be right Diachi.. It's just based on lucks.. Some may get good products and some may get damaged products. Mine was not that cheap, but I don't understand what's the real problem with my watch. May be I should've been more careful while choosing a product.

Just looking at those light blue glasses makes me think they are worthless. I have some inexpensive red and green glasses that do protect against 300 mW red lasers and lower power 532nm too. Never got the blue ones, though. I used the red pair to measure the amount of 808nm light left over from a 532nm and found it doesn't exists as a collimated beam in the low power greens. I used a spectrometer to measure it.

The difference is that with safety equipment failure can result in harm.

If your watch doesn't keep time well, your mp3 player sounds awful or your smart watch turns out to be rather dumb, you're out a little bit of money.

If you rely on safety goggles you can lose an eye when they are faulty.

One bit of luck with safety goggles is that you can actually test them by shining the laser through them and measure how much dimmer the beam gets. It could be so that after a while the beam burns a hole through, but you get an idea of how long that takes and these things are usually intended to protect against brief accidental exposures (reflections and such), not for purposely staring into lasers.

It's not all about price though. You CAN get $10 goggles that will protect you at OD 3+ from 445 nm lasers and take over a minute to burn through with a couple of watts. You can also get $50 goggles that are only OD2 or so leaving brief relections from lasers that produce a few watts so bright that you cannot blink fast enough to save your eyes.

These are logarithmic scales, if you have a 2 watt laser, OD3 glasses will render them to be effectively 2 mW, dangerous but not likely to cause permanent damage. If they are OD2 instead, 20 mW will remain, too much to even blink against.