There's a partial solar eclipse occurring on 29 March 2025, visible from the UK, Europe and parts of the USA, and you'll need safe eclipse glasses to see it.
Solar eclipses are amazing, but they involve looking directly at the Sun and, as such, require safe equipment to do so.
Some observers choose to use a solar telescope to get close-up views of the action, but a good, certified pair of solar eclipse glasses will enable you to observe the event safely too.
If you want to use solar eclipse glasses to observe a solar eclipse, you need to make sure they are properly certified and safe to use.
Solar eclipse glasses use solar filters. These filter sunlight, enabling safe observation of the Sun.
But how can you know whether or not your solar eclipse glasses are safe?
The American Astronomical Society has released a guide to choosing the right eclipse glasses, and what to avoid.
What to know when choosing safe eclipse glasses
The totally eclipsed Sun (when the Moon covers the entire solar disc) is technically safe to look at without eye protection (but only attempt this if you know what you are doing).
During the partial phases of a total solar eclipse, and throughout a partial eclipse, the Sun must be observed through safe solar filters such as certified eclipse glasses.
Safe solar eclipse glasses block all but a small portion of the Sun’s ultraviolet, visible and infrared light, preventing damage to eyesight.
Solar filters that provide safe views of the Sun generally transmit between 1 part in 100,000 (0.001%) and 1 part in 2,000,000 (0.00005%) of its visible light.
Look for the International Organization for Standardization (ISO) mark, the ISO 12312-2 standard for filters for direct observation of the Sun.
Beware false certification! Check for a manufacturer's report showing compliance with ISO 12312-2 based on tests at an accredited laboratory.
The AAA says it has come across test reports that are "at best questionable and at worst clearly bogus".
Unsure? Check the American Astronomical Society's list of vendors of safe solar viewers, listing products the AAS says it has tested for compliance with safety regulations.
Ignore claims that NASA approves or endorses a product. "NASA doesn’t do that," the AAA says.
The exception to the rule, the AAS says, is American Paper Optics in Tennessee, which NASA selected to make its eclipse glasses.
Ignore claims of glasses that block 100% of ultraviolet (UV) and infrared (IR) radiation. Filters that meet the ISO standard transmit small, safe amounts of UV and IR radiation.
To be really safe, observe an eclipse indirectly using solar projection or casting shadows using a kitchen colander! More about this in our guide on how to safely view a solar eclipse.
Find out more by visiting the AAS's guide to safe solar eclipse glasses
Are you observing a solar eclipse? Share your experience and images with us by emailing contactus@skyatnightmagazine.com
