The most important aspect of any solar eclipse is eye safety. While it's perfectly safe to view a solar eclipse if you follow safe solar viewing procedures, you can cause permanent eye damage or even blindness if you attempt to view an eclipse incorrectly.
You must use special eclipse safety glasses to view a partial eclipse, an annular eclipse, and the partial phases of a total eclipse. Although it may be tempting to look directly at an eclipse with unprotected eyes when so much of the Sun is obscured, the small amount of light emitted during even a 99.9 percent partial eclipse is still dangerous. The only time it's safe to look at a total eclipse without proper eye protection is during the very brief period of "totality" when the Sun is 100 percent blocked by the Moon. If you're in a location where the eclipse won't be total, there is never a time when it's safe to look with unprotected eyes.
Make sure that your eclipse safety glasses are certified as meeting ISO standards for safe solar viewing. Take care to purchase your glasses from a reputable seller and be wary of knockoff glasses that claim to be safe but aren't. Already, there are reports of bogus eclipse glasses made by a company called Solar Eclipse International. Be very careful and don't use any product unless claims of safety can be verified. We recommend the products made by Rainbow Symphony. A variety of eclipse safety glasses and handheld solar viewers made by Rainbow Symphony can be found in our eclipse store. Before using your glasses or viewers, make sure that they are not damaged in any way and that you read all of the safety instructions that came with them. Children should always be supervised when using eclipse safety glasses and handheld solar viewers.
Unless a product has been specifically designed for safe solar viewing and has been certified as meeting international standards for such products, it's best to assume that a device, method, or instrument is unsafe. Don't risk it! Unfortunately, the media doesn't always get it right and there is a great deal of misinformation in print and online about what's safe and what isn't. Items such as regular sunglasses, smoked glass, exposed film, medical x-rays, homemade filters, and many others are all unsafe. You can use welder's glass to view an eclipse, but it must be #14 welder's glass; any rating below #14 is not safe. It's also safe to view an eclipse using indirect methods, such as projecting an image of the eclipsed Sun onto a white screen. Our eclipse store includes several indirect viewing instruments. You can also search online for "pinhole projector" and follow the instructions provided by a trusted organization like NASA to make your own.
If the eclipse will be total in your location, don't remove your glasses until the very last bit of the Sun is gone, including "Baily's beads" and the "diamond ring." Again, it's only safe to look with unprotected eyes when the Sun is 100 percent blocked by the Moon and only the soft wisps of the solar corona are visible. Once totality begins, it's important to know exactly when totality will be ending in your precise location so that you can once again put on your eclipse glasses before the first brightness of the exposed Sun is revealed.
Note that attempting to view the Sun using cameras, binoculars, telescopes, or other optical devices without proper filters is extremely hazardous and can permanently damage the eyes in an instant. These devices need specially designed solar filters that fit snugly on the front end (the Sun side) of the device. Never attempt to view the Sun through an optical device using eclipse glasses or any type of filter that attaches to the viewing side (as opposed to the Sun side) of the instrument; the focused light will destroy the filter and enter and damage your eyes. Since viewing or photographing a solar eclipse with an optical device requires specialized equipment and knowledge, we recommend consulting with a qualified astronomer or just enjoying the eclipse with your own eyes (using safe solar viewing procedures, of course).