Figure 4.
Left: spherical-equivalent refractive corrections plotted as a function of age for monkeys reared with diffusers that had either 4 or 8 mm apertures centered over the pupils of both eyes.56 The treatment lenses provided unrestricted vision for the central 24 or 37 degrees of the retina; the rest of the retina experienced severe form deprivation. The shaded area represents the 10th to 90th percentile range of ametropias for control monkeys. Middle: ametropias measured at ages corresponding to the end of the lens-rearing period for the right eye of individual control monkeys (open symbols) and monkeys that were rearing with either peripheral form deprivation or peripheral hyperopic defocus.53 Right: changes in refractive error produced in chickens by treatment lenses with zero-powered central zones and +5D peripheral zones (filled circles) plotted as a function of the diameter of the central zone.51 The open diamond represents the changes in refraction produced by a +5D single-vision lens.