(AL.com) — The Great American Solar Eclipse will have hundreds of millions of people looking to the sky on Aug. 21 to see the moon block out the sun.
You will need special glasses or other equipment to safely see the eclipse, even if you're not in the 70-mile path of totality that stretches from Oregon to South Carolina. Wonder why?
According to NASA, it all has to do with the limitations of the eye and the brightness of the sun.
During an eclipse, people turn their eyes to the sun for a longer period of time and that can cause damage. The sun's brightness is enough that staring at it for even a short period of time it can produce enough light to damage individual retinal cells.
An example of this is when you look at the sun and then glance away and still see a spot as big as the solar surface appeared to your eye.
"Even when 99 percent of the sun's surface (the photosphere) is obscured during the partial phases of a solar eclipse, the remaining crescent Sun is still intense enough to cause a retinal burn. Note, there are no pain receptors in the retina so your retina can be damaged even before you realize it, and by then it is too late to save your vision," NASA said.