Do Sunglasses Protect Eyes in a Solar Eclipse?
Never look directly at the Sun. You can seriously hurt your eyes, and even go blind. Proper eye protection, like eclipse glasses or a Sun filter, is the only safe option. Sunglasses don't work.
Next Annular Solar Eclipse: Sun, Jun 21, 2020 … See animation
How Not to Watch Solar Eclipses
According to NASA, the following materials should never be used to view a solar eclipse:
- sunglasses of any kind
- color film
- medical X-ray film
- smoked glass
- floppy disks
The Sun’s UV radiation can burn the retinas in the eyes leading to permanent damage or even blindness. This can occur even if your eyes are exposed to direct sunlight for just a few seconds.
Safely Watch a Solar Eclipse
The only way to safely view the Sun – eclipsed or not – is to either project or filter the Sun's rays.
Projection works well. You can make your own box projector or use a telescope or binoculars. However, don't look through the telescope’s eyepiece or side-mounted finder scope while projecting the Sun's image onto a screen.
If you are not the DIY type, the American Astronomical Society has compiled a list of vendors where you can buy safe eclipse glasses.
NASA recommends welder's glasses rated 14 or higher. These can be found at your local welding supply store. Keep in mind that welder glass grading may be different in different countries.
You can use special solar filters to watch the Sun during a solar eclipse, but use the proper type of solar filter that is designed for eclipses. Check that filters do not crack under the Sun’s magnified and focused intensity. Solar filters must be treated with care, or they can quickly become damaged and unsafe to use.