Fact Check: Are eclipse glasses safe?

Are Eclipse Glasses Safe?

The safety of eclipse glasses has become a topic of discussion as the annular solar eclipse approaches on October 14, 2023. The claim in question is whether these glasses are indeed safe for viewing the eclipse. Eclipse glasses are specifically designed to protect the eyes from harmful solar radiation, but concerns about their safety and reliability have been raised, particularly regarding the quality and compliance of various brands with safety standards.

What We Know

Safety Standards: Eclipse glasses must comply with the ISO 12312-2 international safety standard, which ensures they are thousands of times darker than regular sunglasses and provide adequate protection against solar radiation 2 10.
Inspection Guidelines: Users are advised to inspect their eclipse glasses before use. They should be discarded if they are scratched, punctured, torn, or otherwise damaged 6 10.
Usage Instructions: It is crucial to wear eclipse glasses at all times when looking at the Sun during an eclipse, including partial phases. Regular sunglasses do not provide sufficient protection 2 4.
NASA's Position: NASA emphasizes that they do not endorse any specific brand of eclipse glasses, but they provide guidelines on how to determine if glasses are safe 1 2 4.
Potential Risks: Looking at the Sun without proper eye protection can lead to serious eye damage, including solar retinopathy, which can occur even during partial eclipses 3 5.

Analysis

Source Evaluation

NASA Sources: The information from NASA (sources 1, 2, 3, 4, and 5) is highly credible due to NASA's authority in scientific research and public safety. They provide clear guidelines based on established safety standards and extensive research on solar viewing.
Eclipse Glasses USA: This source (8) claims to promote safety and knowledge surrounding solar eclipses. However, it is important to consider potential bias, as the organization may have a vested interest in the sale of eclipse glasses. While they provide useful guidelines, their motivations should be scrutinized.
American Astronomical Society (AAS): The AAS (9 10) is another reputable source that provides guidelines on eye safety during solar eclipses. Their recommendations align with those of NASA, reinforcing the importance of using ISO-compliant glasses.

Conflicting Information

While the majority of sources agree on the necessity of using ISO-compliant eclipse glasses, there is a lack of independent testing data available to the public regarding the quality of various brands. This raises questions about the reliability of some glasses on the market, especially those that may not clearly state compliance with safety standards.

Methodological Concerns

The methodology for determining the safety of eclipse glasses primarily relies on compliance with the ISO 12312-2 standard. However, the enforcement of this standard can vary, and consumers may not have access to comprehensive testing results for specific brands. More transparency in testing and certification processes would be beneficial for consumers.

Conclusion

Verdict: Partially True

The claim regarding the safety of eclipse glasses is partially true. While it is established that eclipse glasses must comply with the ISO 12312-2 safety standard to provide adequate protection against solar radiation, the actual safety of specific brands can vary. Key evidence supporting this verdict includes the emphasis on compliance with safety standards by credible sources such as NASA and the American Astronomical Society, as well as the potential risks associated with improper eye protection during solar viewing.

However, there are limitations in the available evidence, particularly concerning the lack of independent testing data for various brands of eclipse glasses. This uncertainty means that while many glasses on the market are likely safe if they meet the ISO standard, consumers should remain cautious and critically evaluate the glasses they choose to use.

Readers are encouraged to verify the safety of their eclipse glasses and to consult reliable sources for guidance on proper solar viewing practices.