Ambient prism lenses - also known as conjugate prisms, yoked prisms, or performance lenses, transitional lenses or Kaplan lenses - are used to help improve ambient vision.
Ambient vision is the visual system related to spatial organisation. This includes posture, movement, as well as the perception of posture and movement.
Some people believe that ambient lenses can be used to improve posture and co-ordination in children with autism who have problems with ambient vision.
Please see: Ambient Prism Lenses and Autism Publications