Richard Hansler said he's not retiring as long as he's having fun working.
Age: 89
Previous career: Research scientist with General Electric
Business: Co-founded LowBlueLights.com
Richard Hansler's "light bulb moment" happened in 2005. With over four decades of experience as a research scientist at GE, he wanted to focus on creating lighting products that wouldn't interfere with people's natural sleep cycles.
At age 81, he co-founded LowBlueLights.com, which makes bulbs that don't emit blue light, eyeglasses that block blue rays from artificial lighting, and other items.
The desire to create safer products drove him to start a business later in life, said Hansler. "For many years I developed bright light sources," he said. "But after I retired I discovered that bright light could be harmful. I felt obligated to do something about it."