A total solar eclipse will track across parts of Greenland, Iceland, northern Russia, Spain, and Portugal on August 12, offering millions of observers a rare celestial event. According to the Institute of Astrophysics of the Canary Islands, this stellar alignment marks the first of three eclipses anticipated over Spain across a two-year period, requiring proper eye protection for safe direct viewing.
Understanding the Path of Totality and Partial Phases
A total solar eclipse takes place when the moon moves directly between Earth and the sun, obscuring the sun’s face entirely. Observers located inside the path of totality—where the lunar shadow completely covers the sun—will experience the full phenomenon. Because this specific event unfolds during the evening over Spain, viewers will witness a rare sunset eclipse featuring a crescent sun setting after the peak of totality.
People situated outside the path of totality will catch a partial solar eclipse, during which the moon blocks only a portion of the solar disc. This partial phase will sweep across the northern United States, Canada, wide swaths of Europe, and northwestern Africa. According to NASA, the single moment it remains safe to view the sun without protective gear is strictly during the brief window of absolute totality when the moon completely masks the light. Any emerging sliver of light signals an immediate need for eye protection.
Preventing Permanent Eye Damage From Solar Radiation
“Even the 1% of the Sun’s surface that remains visible emits enough radiation to permanently damage the eye’s light-sensitive cells,” warns the Institute of Astrophysics of the Canary Islands. Direct observation of the sun without adequate filtration can lead to permanent vision disruption or blindness. Medical documentation from the 2017 total solar eclipse highlights a case where a young woman was diagnosed with solar retinopathy—retinal damage caused by solar radiation exposure—in both eyes after using substandard viewing glasses.
Medical professionals emphasize that solar retinopathy has no medical treatment. While symptoms may occasionally fluctuate, the condition remains permanent. Standard sunglasses fail to provide sufficient protection because they lack the required density, whereas certified solar viewers and eclipse glasses are manufactured to be 100,000 times darker to meet international safety benchmarks.
Store them at room temperature in their original packaging or an envelope to prevent wear, and wipe lenses gently with a clean tissue rather than using wet wipes or moisture.
Certified Equipment and Alternative Viewing Methods
To view the eclipse safely, observers must utilize certified ISO 12312-2 compliant eclipse glasses or handheld solar viewers. Alternatively, optical devices such as telescopes, binoculars, and cameras require dedicated solar filters mounted on the front element. The American Astronomical Society maintains a curated registry of approved manufacturers and verified resellers for glasses, camera filters, and smartphone attachments.
For those lacking certified glasses, indirect viewing methods offer a safe alternative. A pinhole projector—such as a small hole punched into an index card—allows viewers to stand with their backs to the sun and project an image of the crescent onto the ground or a nearby surface. Natural objects with small apertures, including colanders, straw hats, crossed fingers, or the dappled spaces beneath the leaves of a leafy tree, create identical projection patterns without risking eye safety.
Did You Know? Welding filters with a shade number of 12, 13, or 14 made from tempered glass or metal-coated polycarbonate can provide safe viewing because international safety standards were partially derived from them, though the sun will appear green instead of white or yellowish-orange.
Frequently Asked Questions
Can I use regular sunglasses to watch a solar eclipse?
No. Standard sunglasses do not protect eyes from solar radiation during direct observation. Certified eclipse glasses are 100,000 times darker and meet strict international safety standards.
Do certified eclipse glasses expire?
According to the American Astronomical Society, ISO 12312-2-certified viewers do not expire and can be kept indefinitely, provided they remain completely undamaged, un-torn, and free of scratches.
What should I do if I wear prescription eyeglasses?
Keep your regular eyeglasses on and place the eclipse glasses directly over them, or hold a handheld solar viewer in front of your prescription lenses, as advised by the American Astronomical Society.
Is it safe to look through a camera lens while wearing eclipse glasses?
No. According to NASA, you must never look at the sun through an unfiltered optical device—including camera lenses, telescopes, or binoculars—while wearing eclipse glasses, because concentrated solar rays can burn through the filters and cause severe eye injury.
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