LOS ANGELES (CBS) Leonard Bates was 9 when he saw his first eclipse. The 80-year-old made his own viewer instead of using solar glasses.
"I didn't think it was necessary to buy smoked glass, so I smoked some glass myself with a candle," Bates said.
That decision cost him. Bates permanently lost some vision in his right eye.
"There was a spot right at the center of my right eye, my focus, that was just a blur," he said.
Millions of Americans are getting ready to view the next eclipse on Aug. 21, but Dr. Russell Van Gelder from the University of Washington School of Medicine warns blindness is a risk if you don't have proper eye protection.
"It's so dangerous for people to look at the sun even for brief periods of time because you can cause permanent damage to the retina. We call it solar retinopathy and it's really very close to burning a hole in the retina," Van Gelder said.
The only one way to safely view a partial or total eclipse is with certified solar glasses, simple sunglasses are not enough. The American Astronomical Society has a list of reputable eclipse glasses and hand-held viewers on its website stamped with the approval code ISO 12312-2.
"The other piece of advice I have is when you're watching the eclipse with your children, be sure your kids have their eye protection on. It's very exciting for them and they want to take the eye protection off," Bates warned.
"Be very, very careful. The warnings that you hear are right," Bates said.
Bates still has vision in his left eye. He says this time around, he'll watch the eclipse on TV.