Doctors in Japan are developing a new way to repair damaged eyes using cells taken from the mouth.
By Richard Black
BBC science correspondent
These cells are so-called stem cells which, when cultured under the right conditions in the laboratory, have the ability to grow into different types of tissue.
So far, the treatment is only in the early stages of human trials. Nevertheless, it is showing a promising rate of success.
The research, performed at the Kyoto Prefectural University of Medicine, has been presented at a medical meeting in Japan.
Tens of thousands of people each year suffer damage, either from disease or accident, to the front part of their eyes - the cornea.
This can only be repaired by grafting on new corneal tissue taken from someone else.
Many hospitals and clinics store eye tissue for this purpose. But people who have had this treatment have to take powerful and sometimes unpleasant drugs to stop the body's immune system rejecting the graft.
Even so, rejection often occurs.
Now doctors in Japan have come up with another approach. This involves growing a new segment of cornea using cells taken from the patient's mouth.
The Kyoto team has found a way to encourage the mouth stem cells to become corneal cells.
Because the cells come from the patient's own body, no drugs are needed to prevent rejection.
Speaking at the Japanese Society for Regenerative Medicine meeting in Kobe, the team reported treating nine patients, of whom eight recovered their sight.
Dr Nigel Fullwood, from the University of Lancaster, UK, a regular collaborator with the Kyoto team, told BBC News Online: "It's a particular issue in Japan because there's a shortage of eyes to take grafts from.
"People are reluctant to donate them to eye banks." He also said: "The team have reported on these nine patients. But in fact they've treated more than that - about thirty."
Commenting on the work, Professor Anthony Bron, of Oxford University, said: "This would appear to be a major development. There are some kinds of corneal injury which cannot be treated with a conventional graft, which could potentially be treated this way."
And he added: "One of the big advantages is that people receiving this treatment wouldn't need immunosuppressive drugs."