Josh Silver delivers his brilliantly simple solution for correcting vision at the lowest cost possible -- adjustable, liquid-filled lenses. At TEDGlobal 2009, he demos his affordable eyeglasses and reveals his global plan to distribute them to a billion people in need by 2020.

Can architects re-engineer their design process? Joshua Prince-Ramus shows how the results can be spectacular. He walks us through his fantastic re-creation of the Wyly Theater as a giant "theatrical machine" that reconfigures itself at the touch of a button.

What if every home had an early-warning cancer detection system? Researcher Joshua Smith is developing a nanobiotechnology "cancer alarm" that scans for traces of disease in the form of special biomarkers called exosomes. In this forward-thinking talk, he shares his dream for how we might revolutionize cancer detection and, ultimately, save lives.

When Joshua Prager was 19, a devastating bus accident left him a hemiplegic. He returned to Israel twenty years later to find the driver who turned his world upside down. In this mesmerizing tale of their meeting, Prager probes deep questions of nature, nurture, self-deception and identity.

Our government is broken and we have to fix it. Josh Silver, founder and director of non-profit organization RepresentUs, walks through the lines that show what's wrong with legal corruption in our government, how we fix it, and what you can do about it.