Charles Darwin described the eye as an 'organ of extreme perfection and complication'. How this engineering marvel of nature forms out of a few cells in the developing embryo has been the big question for Veronica van Heyningen, emeritus professor at the MRC's Institute of Genetics and Molecular Medicine at the University of Edinburgh.

Veronica is a world lead in the genetics of the development of the eye. She tells Jim Al Khalili about her part in the discovery of a gene called Pax-6 which turned to be a master builder gene for the eye, in all animals which have eyes - from humans to fruit flies.

As she explains, further research on this gene may eventually help people with the genetic vision impairment, Aniridia. It was Veronica's research on patients with this condition which led to the gene's final discovery. She tells Jim about why it's important for scientists to engage in public discussion on the ethical implications of their work.

Veronica also talks about her arrival in Britain as an 11 year old. Her family escaped from communist Hungary in 1958. Both of her Jewish parents had been sent to Nazi concentration camps during the Second World War.