NASA dubbed this image a “diamond ring” eclipse — the key moment when the moon is almost completely covered by the sun. It can be dangerous to watch a solar eclipse from Earth. NASA says the solar radiation that reaches the Earth “ranges from ultraviolet (UV) radiation at wavelengths longer than 290 nm to radio waves in the meter range.” The tissues of the human eye transmit a substantial portion of that radiation to the light-sensitive retina at the back of the eye. Overexposure to this radiation can result in retinal burns. During a partial or annular eclipse, or even when 99 percent of the sun is covered, enough radiation is still entering the eye to cause significant damage. The sun should only be observed through special filters.