In 1882 a baby girl caught a fever that was so fierce she nearly died. She survived but the fever left its mark - she could no longer see or hear. Because she could not hear she also found it very difficult to speak.

So how did this child, blinded and deafened at 19 months old, grow up to become a world-famous author and public speaker?

The fever cut her off from the outside world, depriving her of sight and sound. It was as if she had been thrown into a dark prison cell from which there could be no release.

Luckily Helen was not someone who gave up easily. Soon she began to explore the world by using her other senses. She followed her mother wherever she went, hanging onto her skirts; she touched and smelled everything she came across. She copied their actions and was soon able to do certain jobs herself, like milking the cows or kneading dough, she even learnt to recognize people by feeling their faces or their clothes. She could also tell where she was in the garden by the smell of the different plants and the feel of the ground under her feet.

By the age of seven she had invented over 60 different signs by which she could talk to her family, if she wanted bread for example, she would pretend to cut a loaf and butter the slices. If she wanted ice cream she wrapped her arms around herself and pretended to shiver.

Helen was unusual in that she was extremely intelligent and also remarkably sensitive. By her own efforts she had managed to make some sense of an alien and confusing world. But even so she had limitations.