Survival Guide for the Solar Eclipse: Safe Ways to Observe the Sun

• Conventional sunglasses, CDs, X-ray films, or aluminum foil are ineffective and unsafe, as they do not filter infrared light, risking irreversible retinal damage.
• Only eclipse glasses compliant with the ISO 12312-2:2015 standard are approved for safe viewing.

Why Direct Sun Observation is Dangerous

• Solar radiation includes invisible UV and infrared light that cause distinct eye damage.
• UV-B causes photokeratitis (painful inflammation), while UV-A penetrates to the lens and retina, contributing to cataracts and macular degeneration.
• Infrared radiation causes 'solar retinopathy' by overheating retinal tissues; since the retina lacks pain receptors, victims may not realize they are suffering permanent vision loss until hours later.
• During an eclipse, the lower light intensity causes pupils to dilate, allowing more harmful UV-A and infrared rays to enter the eye compared to a standard sunny day.

Equipment Standards and Precautions

• ISO 12312-2:2015-certified glasses are made of black polymer infused with carbon particles that block 99.99% of solar energy.
• To verify authenticity, check for the manufacturer's name, address, and the CE mark; if you can see common objects like furniture or trees through them, the glasses are fake.
• Do not use glasses older than 15 years or those with scratches, as these degrade protection and can focus light directly onto the retina.
• Never look through telescopes or binoculars while wearing eclipse glasses, as the lenses act as magnifying glasses that can melt the filter; use dedicated solar filters placed on the front objectives.
• The only exception is the 'totality' phase, where the sun is completely covered; glasses must be put back on immediately when the first point of light reappears.

Indirect Observation Methods

• When specialized glasses are unavailable, use indirect projection methods.
• A kitchen colander can project the crescent sun shapes onto the ground.
• A homemade pinhole camera, built with a cardboard box, paper, tape, and foil, provides a 100% safe and educational way to observe the event.