Solar eclipse eye safety
On Aug. 21, 2017, millions of people in the U.S. will see day turn to night as a total solar eclipse passes over North America. The last time this happened from coast to coast was 1918. Temperatures will drop rapidly as the moon completely covers the sun. You will be able to see the spectacular colors and light of the sun’s atmosphere, a sight revealed to us only during a total solar eclipse.
Watching a solar eclipse is a memorable experience, but looking directly at the sun can seriously damage your eyes. Staring at the sun for even a short time without wearing the right eye protection can damage your retina permanently. It can even cause blindness, called solar retinopathy. The lenses in your eyes act like a magnifying glass, one that is 5 times more powerful than a handheld magnifier. Think about how you can use that typical handheld magnifier to focus the sun to burn holes in paper. That’s what happens when you look at the sun without eye protection. You focus the sun’s light on the retina, burning holes in light-sensitive photoreceptor cells, causing blindness.
There is one exception to this rule. There is a brief phase during a total solar eclipse when it is safe to look directly at the sun. This phase is called totality, and it lasts about 2 minutes. It occurs when the moon entirely blocks the sun’s bright face. However, as soon as the sun begins to reappear, put the solar filters back on. The path of totality for the Aug. 21, 2017, total solar eclipse is about 70 miles wide and stretches from Oregon to South Carolina. It passes through Idaho, Wyoming, Nebraska, Kansas, Missouri, Illinois, Kentucky, Tennessee, Georgia, North Carolina and South Carolina. Outside the path of totality, sky watchers will see a partial solar eclipse.
There are no exceptions to the rules for safely viewing a partial solar eclipse. To make sure people have the facts, the UCLA Stein Eye and Doheny Eye Institutes join the American Academy of Ophthalmology to offer these five tips:
- Use specially designed solar eclipse glasses and viewers to block the sun’s harmful rays. They must meet a very specific worldwide standard known as ISO 12312-2. Ordinary sunglasses, even dark ones, are not strong enough to protect your eyes.
- Inspect your solar filter before the eclipse, and do not use it if it has scratched or damaged.
- Another option is to view the eclipse through #14 welder's glass. That is much darker than the shades arc welders typically wear.
- Use solar filters on camera lenses, binoculars, and telescopes.
- Do not use solar eclipse glasses to look through a camera, binoculars or a telescope. The sun can melt the filter and damage your eyes.
For more information to keep your eyes healthy or to find an ophthalmologist near you, visit uclahealth.org/eye.