Does running damage your knees? And is cycling any better? Runner, cyclist, GP and Inside Health regular, Dr Margaret McCartney goes to the new Motion Analysis Lab at Glasgow's Jubilee Hospital and asks orthopaedic surgeon and competitive cyclist Jason Roberts about the latest evidence.

Around 30,000 people a year suffer cardiac arrest - their heart suddenly stops pumping blood around their body - and fewer than one in ten survive. Paramedics and ambulance crews will give CPR and use a defibrillator to try to restart the heart, and for the past 50 plus years, most patients will be given a shot of adrenaline too.

It's said that eyes are the windows to the soul - and certainly looking into other peoples' is the key part of human interaction. But what if one of yours isn't real? Sixty thousand people in the UK have an artificial eye and Europe's largest maxillo-facial laboratory at Queen Victoria Hospital in East Grinstead offers a bespoke service where specialists make individual eyes from live sittings. Susan lost one eye as a child and she tells Mark that her latest prosthesis is her favourite. Why? Because it's almost half the weight of eyes she's had fitted before. Dr Emma Worrall, principal prosthetist, has invented a lighter sphere. In a lightbulb moment sitting in a café stirring a sugar cube into her coffee and watching it melt, Emma tells Mark that she realised she could build the plastic sphere around sugar, drill a tiny hole, then melt the sugar out of the middle! Twenty patients at the hospital are now benefiting from lighter eyes (which means less surgery). And there's another plus. The new eyes float in the swimming pool and the sea!

Producer: Fiona Hill.