MyoVision lenses are specialized lenses manufactured to a person's prescription and mounted in a frame of their choice. They are worn for all visual activities, both reading and distance vision. The lenses are worn as long as myopia progression is considered a risk.
MyoVision lenses create a ring of increased plus power around the central area of clear distance power. This ring of power creates what is called a peripheral myopia which has been shown to slow myopic progression. A promotional video on YouTube claims a reduction in myopia progression of 30% although there are no published journal studies.
Peripheral myopia has been shown to function as a "stop signal" for further growth. When eyes grow longer, they become more myopic so stopping growth is desired. The signals for this growth are in the peripheral retina. You can read about it in the different sections of the Definitions menu. Here's a link to the hyperopic defocus section.
The lenses create a peripheral distortion that sometimes makes adaptation difficult. For the lenses to work, it is necessary to use the central portion of the lens for viewing.
Children are generally very adaptable. It remains to be seen how the lenses will work for those involved in sports or other activities requiring good peripheral vision.
MyoVision lenses are the brand name of a lens currently (2010) marketed in Hong Kong by Zeiss, a major world-wide ophthalmic company. MyoVision lenses are prescription devices that are worn to correct myopia (nearsightedness or shortsightedness) and are normally designed to give clear distance vision with a peripheral blur.
MyoVision lenses are marketed specifically as a treatment to slow myopic progression in children. There is no other reason to wear them.