Solar eclipses are safe to enjoy when you use the right viewing method. The key rule is simple: never look directly at any visible part of the Sun without proper solar protection.

That rule applies before totality, after totality, during partial eclipses, and during annular eclipses. The only exception is the brief total phase of a total solar eclipse, when the Moon completely covers the Sun's bright face for observers inside the path of totality.

Eye safety during a solar eclipse

Use ISO-compliant eclipse glasses

For direct viewing, use eclipse glasses or handheld solar viewers that comply with the ISO 12312-2 international safety standard. They should come from a reputable source and be free of scratches, holes, warping, or damaged film.

Regular sunglasses are not enough, even if they are very dark. They do not block the necessary amount of visible, ultraviolet, and infrared light. Smoked glass, exposed film, CDs, DVDs, and improvised filters are also unsafe.

If you are supervising children, make eclipse safety physical and simple: glasses go on before looking up, stay on while any part of the Sun is visible, and come off only when an adult confirms totality has begun.

Indirect viewing is a great option

You do not need to look at the Sun directly to enjoy an eclipse. A pinhole projector lets sunlight pass through a small opening and fall onto a surface, creating a tiny projected image of the eclipsed Sun.

Stand with your back to the Sun. Let sunlight pass through a small hole in one card onto a second card used as a screen. Watch the projected image, never look through the hole at the Sun.

Tree leaves can do the same thing naturally. The small gaps between leaves act like pinholes, scattering hundreds of crescent Suns onto the ground during the partial phases.

Cameras, binoculars, and telescopes need front filters

Optical devices concentrate sunlight. Looking through an unfiltered camera viewfinder, binoculars, or telescope can cause severe eye injury very quickly, even if you are wearing eclipse glasses.

Any camera lens, binocular, or telescope used for the partial phases needs a solar filter mounted securely on the front, before sunlight enters the optics. Do not use eclipse glasses as a substitute filter behind a magnifying optical device.

During totality, experienced photographers remove solar filters to capture the corona, then replace them before the Sun returns. This timing is unforgiving, which is why accurate contact times matter.

Totality has different rules

Inside the path of totality, the Sun's bright photosphere disappears between second contact and third contact. During that short interval only, it is safe to look at the totally eclipsed Sun with your unaided eyes.

Baily's beads and the diamond ring contain direct sunlight and require solar eye protection. Remove protection only once full totality is established, and restore it before any bright sunlight returns. Annular eclipses have no safe unprotected viewing interval; do not use an app countdown as your sole safety check.

If you are not inside the path of totality, there is no naked-eye viewing window. Even a 99 percent partial eclipse leaves enough exposed Sun to require protection.

Plan safety around your location

Eclipse safety depends on timing. First contact, second contact, third contact, and fourth contact are not the same everywhere. A printed schedule for one city may be wrong for another viewing spot.

Use location-specific contact times, build in a margin, and brief everyone in your group before the eclipse begins. The most relaxed eclipse watchers are usually the ones who made their safety plan before the sky started changing.