Looking directly at the sun can permanently damage your eyes, especially during a solar eclipse. Although eclipses of all kinds occur multiple times a year across the country, people seem unable to resist the excitement when one appears close to home.
Before you start making plans for the next big U. An eclipse is defined as an event where an astronomical object is blocked from view. The eclipses we are most familiar with fall into two main categories: lunar eclipses and solar eclipses. This type of eclipse poses no danger to the observer since you are just looking at light hitting the moon, not directly at a source of light. A solar eclipse, on the other hand, is quite dangerous to look at directly. This type of eclipse occurs when part of the earth is covered in a shadow cast by the moon as it passes in front of the sun.
You can view a total solar eclipse with your bare eyes, but only when the moon completely covers the face of the sun. And if you're really gung ho about looking up at the sun without special spectacles, you could watch the event's progression through a pinhole camera.
Otherwise, NASA recommends putting on a pair of eclipse glasses that meets the current international standard for eye protection, because the ultradark lenses shield your peepers from the sun's harmful rays.
And when gazing at the eclipse with binoculars or another magnification device, make sure the device is equipped with its own solar filter — eclipse glasses alone won't prevent eye damage from magnified sunlight [source: Cofield ]. If you follow these tips, you can take joy in knowing that you're about to witness an awe-inspiring celestial show safely. Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close.
Mobile Newsletter chat dots. Mobile Newsletter chat avatar. This can happen to people who repeatedly look at the sun without any protection, those who stare at the sun for an extended time, or even those who glance through a telescope or binoculars without solar filters. Not many people look at the sun long enough to be blinded by the light, Chou said, but the risk is certainly exacerbated during a solar eclipse. Under normal circumstances, it's more difficult to look at the sun long enough to incur damage because of something called an aversion reflex.
To make matters worse, it's possible to look directly at the sun "with a certain degree of comfort" when the sun is partially covered by the moon, Chou said. Even when the sun is almost completely covered, though, the tiny crescent that remains is still bright enough to burn your retinas.
One thing that makes eclipse blindness particularly dangerous is that a person who looks at the sun long enough to incur damage probably won't notice any of the effects until the next morning, Chou said.
The cells get overloaded, and they're actually still able to function for a little while, but overnight while you're asleep … the cells start lose their function, and then they even start to die depending on exactly how badly they've been affected," he explained.
People who wake up to discover their vision has become impaired may look in the mirror to find their face is a featureless blur, Chou said, or they may try to read the newspaper only to find that there are no words on the page. While peripheral vision is usually spared, the center of vision is affected the worst. That's the part of the retina responsible for seeing in high resolution and in color. Most patients with eclipse blindness are legally blind when they go to see an eye doctor, Chou said.
Unfortunately, the prognosis for these patients is nearly impossible to determine. Statistically, about half of those who are diagnosed with eclipse blindness will recover full vision in six months, he said. The other half either partially recover or are stuck with the problem for the rest of their lives. And when it comes to treatment, there really aren't any options. The only thing doctors can do to help these patients is to treat the case as any other case of visual impairment, Chou said, by teaching the individuals how to get around in the world and function without central vision.
The only time it's safe to look at the sun without eclipse glasses or other solar filters is during totality, when the moon is completely blocking out the sun's rays and only the corona is visible. If you're planning on watching any kind solar eclipse, whether it's of the total, annular or partial variety, you absolutely must use proper eye protection if you want to spare your eyes.
Otherwise, you'll risk long-term or even permanent blindness.
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