New software could allow computer users with disabilities or busy hands to write nearly twice as fast, more accurately and more comfortably than before. The software could also speed up writing on palm-tops and typing in Japanese and Chinese, its developers say.

The package, called Dasher, “exploits our eyes’ natural ability to navigate and spot familiar patterns”, says one of its inventors, computer scientist David MacKay of the Cavendish Laboratory in Cambridge, UK.

An eye-tracking device lets users select letters from a screen. Dasher calculates the probability of one letter coming after another. It then presents the letters required as if contained on infinitely expanding bookshelves.