A graduate has invented a talking shopping trolley that he says could help millions of elderly shoppers.

Ben Charles, 22, has come up with a prototype device that can be attached to trolley handles. It scans products and then relays key information, including price, both on a screen in large type and by voice.

According to his research, three quarters of the UK's 13 million pensioners find it difficult to read prices and information in supermarkets.

Charles, who has a first-class degree in computer-aided product design, hopes to sell the device to a supermarket.