Why do bright lights trigger sneezes?

Chris Smith from The Naked Scientists takes on YOUR questions with Eusebius McKasier from talk radio 702. Could gravity from my first-floor apartment impact my sleep patterm? Why do hearts beat faster when we're excited? What are the consequences of dental surgery? Is prejudice carried in DNA? How does a master-key work? Does exercise and breathing more oxygen increase the ageing process? Why do bright lights cause sneezes? Plus, the single use plastic that saved endangered snails in Bermuda.