AGNES stands for Age Gain Now Empathy Suit, and is a suit created by people at MIT. It allows anyone who puts it on feel the normal physical effects of aging, such as loss of balance and loss of flexibility.
In order to help people thrive as they age, we still must recognize that even if an older person remains physically and mentally fit, there are still physical changes that happen as we age. Acknowledging these physical changes, and allowing designers to experience them, can help make sure that products and services are designed and tested with such things in mind.
One of the creators Joe Coughlin also did a TedxBoston talk called "Aging as an Extreme Sport" (where I first learned about AGNES) that you can see on You Tube.