Safety + Tips
How to observe the eclipse without damaging your eyesight
Watching a solar eclipse is only safe when using systems that reduce the light and block harmful radiation.
Here you will find the advice you need to observe the eclipse in complete safety, from how to choose glasses with a certified solar filter to indirect projection methods that allow you to enjoy the phenomenon without putting your eyesight at risk.
Safety is essential
Watching a solar eclipse without following the safety instructions can damage your eyesight irreversibly. That is why it is so important to take the safety measures detailed below.
What is safe?
Certified eclipse glasses
- Check that they clearly indicate compliance with standard EN ISO 12312-2:2015
- They bear an authentic CE marking
- The manufacturer’s name is clearly visible
- They include instructions for use, warnings and, where applicable, an expiry date
Also check that the filter is in good condition, with no scratches, bright areas or visible damage. If any of these conditions is missing, do not use them.
Specific solar filters
Specific solar filters for telescopes, binoculars or cameras, always placed on the front of the instrument.
Do not look directly at the Sun
Project the image of the Sun onto a screen and look at the screen; never look directly at the Sun.
Use certified glasses and specific solar filters
Avoid looking directly at the Sun and use certified glasses and solar filters specifically designed for that purpose.
It is important: for your safety and to protect your visual health.
“Solar eclipse from Pamplona (1905)”
AGN. Fot_Martinez_Berasain_377
What is not safe?
Ordinary sunglasses
Ordinary sunglasses are not safe for observing the eclipse, even if they are very dark or from a good brand.
Non-certified materials
Smoked glass, X-rays, CDs, DVDs, floppy disks or black plastic.
Homemade filters
Homemade filters for telescopes, cameras or binoculars.
Devices without specific filters
Binoculars, telescopes or cameras pointed at the Sun without a specific filter on the front.
Damaged eclipse glasses
Eclipse glasses that are broken, bent, scratched or lack manufacturer identification are not safe.
You may put your visual health at risk
Using any of the items listed above can seriously damage the cornea, even without you realising it.
For your health, it is important to follow the guidelines recommended in this section.
And my glasses...
are they safe?
Observing a solar eclipse can be a fascinating experience, but doing so without adequate protection can cause serious and irreversible damage to the retina. For that reason, it is essential to make sure that the glasses being used are specifically designed for this purpose and comply with safety standards.
Appropriate ISO standard
Make sure the glasses clearly state that they comply with standard EN ISO 12312-2:2015. This is the only valid standard for direct observation of the Sun. If they only mention ISO 12312-1, they are not safe for eclipses.
Authentic CE marking
If the glasses were purchased in the European Union, they must bear a legitimate CE marking, backed by laboratory testing. It is not enough for it simply to be printed without justification.
Complete labelling
Check that they include the manufacturer’s name, warnings for safe use, storage instructions and, where applicable, an expiry date.
Physical condition of the filter
Do not use glasses with scratched, bent, loose filters, with lighter areas or any visible defect. Even a small imperfection may allow dangerous light to pass through.
Consult reliable sources
Planetariums, astronomical associations and scientific institutions usually recommend products that have passed quality controls.
Check your glasses carefully
Make sure they are specifically designed for viewing the eclipse. It is essential that they meet the requirements set out below.
Safe Use Protocol:
The Ground Rule
To ensure full protection, always follow this order when using your eclipse glasses: before looking at the Sun, direct your gaze toward the ground, put the glasses on properly, and only then lift your head to observe the phenomenon.
Likewise, when finishing observation, first look back toward the ground, and once your eyes are protected from direct light, remove the glasses. This simple step prevents accidental exposure of your retina to solar radiation during the adjustment or removal process.