DO NOT TRY TO VIEW THE SUN DIRECTLY WITH THE NAKED EYE OR THROUGH ANY OPTICAL EQUIPMENT SUCH AS NAKED EYE, CAMERA OR TELESCOPE WITHOUT PROPER SOLAR FILTER.
HUMAN EYE DOES NOT SENSE ANY PAIN IN CASE OF A DIRECT SUNLIGHT!
The Sun can be viewed safely with the naked eye only during the total solar eclipse. Partial eclipses, annular eclipses, and the partial phases of total eclipses are never safe to watch without taking special precautions. Even when 99% of the Sun's surface is obscured during the partial phases of a total eclipse, the remaining photospheric crescent is intensely bright and cannot be viewed safely without eye protection. Do not attempt to observe the partial or annular phases of any eclipse with the naked eye. Failure to use appropriate filtration may result in permanent eye damage or blindness!
Generally, the same equipment, techniques and precautions used to observe the Sun outside of eclipse are required for annular eclipses and the partial phases of total eclipses. The safest and most inexpensive method is to use eclipse glasses. Another way is the projection, in which a pinhole or small opening is used to cast the image of the Sun on a screen placed a half-meter or more beyond the opening. Projected images of the Sun may even be seen on the ground in the small openings created by interlacing fingers, or in the dappled sunlight beneath a leafy tree. Binoculars can also be used to project a magnified image of the Sun on a white card, but you must avoid the temptation of using these instruments for direct viewing. The Sun can also be observed directly only when using specially designed "solar filter" in front of the telescope aperture.
Some Useful Links
Eye Safety and Solar Eclipses
Eye Safety and Solar Observing Techniques
Observing Eclipses Safely
www.eclipse-glasses.com
thousandoaksoptical.com
www.eclipseglasses.co.uk
www.eclips2006.com