The technology — orthokeratology — is designed to correct nearsightedness by keeping special contact lenses in the eyes while you sleep to change the shape of the cornea so that you can see clearly after you remove the lenses.
The effect lasts for about a day or two.
Some Japanese ophthalmologists are using it in clinical tests pending official approval. Eye specialists said guidelines on its application should be prepared to avoid any problems.
The procedure costs about 150,000 yen to 300,000 yen in Japan because eye specialists must import the lenses themselves and hand out prescriptions. The national medical insurance system does not cover it.
This U.S. technology is gaining ground because people can improve their vision without undergoing an operation.