Watching the solar eclipse on 2 August 2027 will be an unforgettable experience, but proper eye protection is essential. Whether you are watching a partial eclipse or experiencing the total solar eclipse of 2 August 2027, knowing when and how to protect your eyes is essential. In this guide, we explain how to safely watch the 2027 solar eclipse, when you need eclipse glasses and what to look for when choosing safe solar viewers
Here is what you need to know to enjoy the eclipse safely.
Why do you need eclipse glasses?
Looking directly at the sun can cause serious eye injury. During the partial phases of a solar eclipse, the sun may appear much dimmer than usual, but the remaining visible portion is still intensely bright.
Ordinary sunglasses — even very dark ones — are not suitable for direct solar viewing.
To look directly at the sun during the partial phases of an eclipse, use special-purpose eclipse glasses or a handheld solar viewer designed for direct observation of the Sun. Safe solar viewers should meet the requirements of the international ISO 12312-2 standard.
What is ISO 12312-2?
ISO 12312-2 is the international standard covering filters intended for direct observation of the sun.
Solar viewers conforming to the standard are designed to reduce visible sunlight to a safe and comfortable level while also providing protection from potentially harmful solar radiation.
However, seeing “ISO 12312-2” printed on a pair of glasses is not, by itself, proof that the product has been properly tested. The American Astronomical Society therefore recommends obtaining solar viewers from reputable manufacturers and suppliers whose products have been tested by appropriately accredited laboratories.
When should you wear eclipse glasses?
For most of an eclipse, the rule is simple:
If any part of the sun's bright surface is visible, use proper solar viewing protection when looking directly at it.
During the partial phases before and after totality, eclipse glasses should remain on whenever you look directly at the sun.
There is one important exception:
During totality
If you are located inside the path of totality, there will be a brief period when the moon completely covers the sun's bright face. Only during this period of complete totality can the eclipse be viewed directly without eclipse glasses. As soon as even a small part of the bright sun begins to reappear, put your eclipse glasses back on before looking at it.
If you are outside the path of totality, there is no safe period for looking directly at the eclipsed sun without proper solar viewing protection.
How to use eclipse glasses correctly
Before the eclipse begins, inspect your glasses carefully. Do not use them if the filter is scratched, punctured, torn, loose or otherwise damaged. When you want to look at the sun:
- Put your eclipse glasses on before looking up at the sun.
- Look at the eclipsed sun through the solar filters.
- When you are finished viewing, turn your face away from the sun.
- Only then remove the glasses.
Children should always be supervised while using eclipse glasses. If you normally wear prescription glasses, keep them on and place the eclipse glasses over them.
Can I use sunglasses instead?
No.
Regular sunglasses are not a substitute for eclipse glasses, regardless of how dark the lenses appear. Special-purpose solar viewers are dramatically darker than ordinary sunglasses and are designed specifically for direct observation of the Sun.
Can I look through my phone, camera, binoculars or telescope?
This requires extra care.
Never look at the sun through an unfiltered camera lens, telescope or binoculars — including while wearing eclipse glasses.
Magnifying optics concentrate sunlight and require special-purpose solar filters mounted securely over the front of the optics. Eclipse glasses worn over your eyes are not a substitute for these filters. NASA and the AAS recommend seeking expert advice before using cameras, telescopes or binoculars for direct solar observation.
Check your glasses before 2 August 2027
Don't wait until the eclipse has already begun.
Before eclipse day:
✓ Use eclipse glasses designed for direct solar viewing
✓ Check that they meet ISO 12312-2 requirements
✓ Obtain them from a reputable source
✓ Inspect the filters for damage before use
✓ Read and follow the manufacturer's instructions
✓ Make sure children know how to use them correctly
If you're travelling to see the eclipse, arranging proper viewing protection in advance is particularly sensible. Demand for eclipse glasses can increase significantly as an eclipse approaches.
Preparing for the 2027 total solar eclipse
On 2 August 2027, a total solar eclipse will be visible from a path crossing parts of southern Europe and North Africa.
For destinations within the path of totality, the event will offer the extraordinary experience of the Sun becoming completely obscured by the Moon. Areas outside the path will experience a partial eclipse.
Wherever you plan to watch, prepare in advance and make safe solar viewing part of your eclipse experience.
