How does looking at an eclipse blind you

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. The only safe time to look at an eclipse is during the totality. While animals may exhibit strange behavior during the eclipse , they know better -- better than humans, anyway -- than to look up.

Photos: People watching eclipses through the years. There's no sense of wonder or excitement here. Even as recently as the s, eclipses were still regarded with fear. This group gathered in a window to view the total solar eclipse over London through smoked glass -- touted as a safe method at the time -- in June Hide Caption.

Clay cuneiform tablets are the first records of eclipses that we have. This one, dated from to B. In , a group of riders dismount to observe a total solar eclipse on Haradon Hill near Salisbury, England.

Notice the cloudy and threatening sky. King Louis XIV and the ladies of the court on the terrace of Marly castle, watching the total solar eclipse of Artist Johann Christian Schoeller depicted a crowd watching a total solar eclipse July 8, It occurred across China, Russia and parts of Eastern Europe.

This chromolithograph depicts people watching the total solar eclipse in Tarragona, Spain, in The Kew photoheliograph, the first astronomical instrument specifically designed for photographing celestial objects, was conceived by British astronomer and physicist Warren de La Rue in It was built for the Royal Society by Andrew Ross.

In , it was taken to Rivabellosa, in northern Spain, where it was used to photograph a total solar eclipse. Astronomers Maria Mitchell, left, Cora Harrison, center, and Maria's sister Phebe traveled to Denver to watch the total solar eclipse of Their telescopes are pointing toward the center of the solar system.

The "eclipse party" from Vassar College was featured in newspapers, and Maria Mitchell was highly regarded in her day as a pioneering female scientist. A crowd in a California town observes the total eclipse of the sun in September Amateur astronomers and spectators got up early to witness and photograph a total eclipse of the sun in London in On August 31, , people squinted through protective film to see a partial eclipse of the sun from the top deck of New York's Empire State Building.

Parisians watching the solar eclipse with the help of smoked glass on the steps of Sacre-Coeur, Paris, France, in October Students using the pinhole technique to view the solar eclipse on February 27, Students at Sydney University protect their eyes from the total solar eclipse by looking through pieces of cardboard and film. An astronomer with Educational Expedition International in Mauritania's desert uses astronomical equipment to view a total solar eclipse in On February 26, , eclipse enthusiasts, photographers and television crews gather to watch the solar eclipse in Goldendale, Washington.

A Cambodian monk watches the beginning of a full solar eclipse with safety glasses in October , during a total eclipse at Angkor Wat. Thousands of tourists and locals witnessed the eclipse at the 12th century monument. Healing occurred during the first month after the eclipse, the researchers reported in the journal Graefe's Archive for Clinical and Experimental Ophthalmology, but by 18 months, whatever damage remained was permanent up to 15 years later.

So, while it might be tough to go totally blind by looking at an eclipse, doing so without proper protection could leave a long-lasting stain on your vision. The only safe way to view an eclipse , according to NASA, is to use specially designed sun filters, often available at telescope stores, or to wear No.

Pinhole viewers — essentially a hole in a piece of cardboard or paper — can also be used to view the eclipse indirectly by casting a shadow of the sun on the ground or on a screen. If you don't have certified eclipse viewers, you can also make a pinhole camera viewer that will allow you to see the eclipse without looking at the sun directly.

Originally published on Live Science. Stephanie Pappas is a contributing writer for Live Science covering topics from geoscience to archaeology to the human brain and behavior.

A freelancer based in Denver, Colorado, she also regularly contributes to Scientific American and The Monitor, the monthly magazine of the American Psychological Association. Stephanie received a bachelor's degree in psychology from the University of South Carolina and a graduate certificate in science communication from the University of California, Santa Cruz.

Even during the total solar eclipse, the total eclipse may last only a short period of time, and if you are looking towards the sun as the moon moves away from blocking the sun, you might get a solar burn on your retina which can cause permanent damage to your eyes. Talk with your eye care professional to determine the best viewing option for you. Below are a few common ways to safely watch a solar eclipse:. Pinhole projection : This is the safest and most inexpensive way to watch a solar eclipse.

This helps you avoid looking directly at the eclipse by using a projected image. This do-it-yourself project includes making a pinhole in a cardboard paper with the sun on one side and a piece of paper three feet away without obstruction to project the image on the other side.

Keep in mind not to look through the pinhole at the sun. This glass will reduce the harmful rays that are emitted during the eclipse. Do not use if there are any scratches or damage to the glass. Mylar filters : Aluminized mylar plastic sheets are available as eclipse vision glasses or can be cut and made into a viewing box. Do not use if there are any scratches or damage to the sheet. Other ways : Other ways to safely watch a solar eclipse is on television or at the planetarium. Be careful about how you watch a solar eclipse.