Not yet done inventing
senior entrepreneur gallery richard hansler
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

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, which makes bulbs that don't emit blue light, eyeglasses that block blue rays from artificial lighting, and other items.

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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."

- Last updated March 20 2013 05:58 AM ET
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