London Times
Night contact lens brings a clear day


July 17 2000

A new night-time contact lens which allows short-sighted people to wake up and see clearly has been proved effective in the first independent tests. The lenses temporarily correct the focus of the eye while the wearers sleep, so they can dispense with lenses or spectacles during the day.

However, the malleability of the cornea, which allows such reshaping, also means that the eye gradually relaxes back into its old short-sightedness. The wearer must therefore use them at night at least two or three times a week.

The theory, which is called orthokeratology, has been known about for decades, but was only developed in the last few years due to advances in oxygen-permeable lenses that are safer to sleep with.

Joseph Barr, professor of optometry at Ohio State University, carried out the independent tests, published in the journal Optometry.