I have some questions about "counterfeit" eclipse viewing glasses.

[Towlie]

I have some eclipse viewing glasses that I got from Amazon over a month ago. I tried a pair when I got them and they seem to work just as they should. The sun is reduced to a clearly visible disk and I felt no sign of discomfort or eye strain looking directly at the sun on a clear afternoon.

Amazon just notified several of their customers, including me, that the glasses we got from them aren't properly certified, and they recommend that we not use them to view the sun. (See https://www.democraticunderground.com/10029453375)

Since the glasses don't appear to pass an uncomfortable amount of visible light, is the reason for this supposed danger that they might pass harmful radiation in the infrared or ultraviolet regions of the spectrum? If so, is it infrared, ultraviolet, or both?

If it's ultraviolet radiation, I had cataract surgery in both eyes and my lens implants are opaque to ultraviolet light. Can I expect that to help protect my retinas?

Thanks for any information.

[freddyvh]

1. Amazon is giving me a refund

After I purchased 5 glasses.
They had the "certified" stamp on them from the ISO

It makes me wonder if any of the glasses are trustworthy

[GeorgeGist]

2. How can you tell if your solar viewer is not safe?

You shouldn't be able to see anything through a safe solar filter except the Sun itself or something comparably bright, such as the Sun reflected in a mirror, a sunglint off shiny metal, the hot filament of an unfrosted incandescent light bulb, a bright halogen light bulb, a bright-white LED flashlight (including the one on your smartphone), or an arc-welder's torch. All such sources should appear quite dim through a solar viewer. If you can see lights of more ordinary brightness through your eclipse glasses or handheld viewer, and you're not sure the product came from a reputable vendor, it’s no good. Safe solar filters produce a view of the Sun that is comfortably bright (like the full Moon), in focus, and surrounded by dark sky. If you glance at the Sun through your solar filter and find it uncomfortably bright, out of focus, and/or surrounded by a bright haze, it’s no good. You should contact the seller and demand a refund or credit for return of the product, then obtain a replacement from one of the sources listed on our reputable-vendors page.

https://eclipse.aas.org/eye-safety/iso-certification

[Towlie]

3. That article logically contradicts itself.

The glasses are either safe or not safe. The article first says this:

How do you know if your eclipse glasses or handheld solar viewers are truly safe? You need to know that they meet the ISO 12312-2 (sometimes written as ISO 12312-2:2015) international safety standard. Filters that are ISO 12312-2 compliant not only reduce visible sunlight to safe and comfortable levels but also block solar UV and IR radiation.

Unfortunately, you can't check whether a filter meets the ISO standard yourself — doing so requires a specialized and expensive piece of laboratory equipment...

Then later it says what you quoted above:

How can you tell if your solar viewer is not safe? You shouldn't be able to see anything through a safe solar filter except the Sun itself or something comparably bright... (etc.)

This is a direct contradiction. First it says you need assurance that invisible wavelengths are blocked, then it says you can judge according to what's visible.

[Nitram]

4. I think the point is that even if glasses block out all visible light, they may pass UV light, which

is the most harmful frequency. Basically, the glasses might be ok but if they are not certified, there is no way of knowing, and not worth the risk. I got online to replace the glasses I got from Amazon (a month ago) as soon as I got their email, and almost every certified product already had a backorder time of two or more weeks. The person I got on the chat helpline finally located some children's size glasses which were certified and immediately available.

[Jim__]

5. I don't believe the intended meaning of that paragraph is a contradiction of the previous statement.

It emphasizes the not in the question: How can you tell if your solar viewer is not safe?

My reading of that is: failing that test means your viewer is not safe, passing it does not guarantee that it is safe. If that is their intended meaning, they should clarify their statement.

[Warpy]

6. Not sure I'd trust glasses, at all

I've been blind once, don't want to be blind again.

I'd stick to the two pieces of cardboard, one with a pinhole, the other with a white surface to focus the image on.

[Canoe52]

7. That's, what we're doing.

They also say welding goggles will work, but I've done welding and you can't see much through them, even the sun.

[CaliforniaPeggy]

8. Here's an article that talks about solar glasses certification and how to be safe:

https://eclipse.aas.org/eye-safety/iso-certification

Embedded in this article is a list of manufacturers who have been investigated and are deemed reliable. All the solar glasses I have are on this list.