Myopic Progression is based on the retinal “IMAGE SHELL”
Myopic Progression is multifactorial. It is related to poor optical imaging by refractive eyewear and contact lenses, genetics, time spent outdoors, time spent on intensive near point work, time spent on digital technology and other factors.
The eye is ever-growing based on environmental signals and stress placed on the eyes.
The simple essence of myopia control is to focus all incoming images into the fovea centralis and bring parafoveal defocused images (the image shell) into focus to prevent accommodative stress.
The image shell is where light is properly focused onto the center of the retina (fovea) but the light from the lenses through the pupil are defocus in the peripheral or para foveal area forcing the eye to work harder to try to focus this “out of focus” light.
Image shells on the retina. Once the eye elongates in myopia, optical images from spherical lenses no longer fall on the retinal plane. The peripheral images are out of focus falling on a plane behind the retina. It is thought that the relative hyperopic error created is the stimulus for axial elongation. Current optical treatments move the peripheral focus in front of the retina.
Normal eyeglasses and contact lenses will not correctly focus light onto the peri-foveal are and as such, normal glasses or contacts may exacerbate myopia progression.
But there are excellent alternatives: Orthokeratology, multifocal soft contact lenses, low dose atropine, customized (DIMS) Defocus Incorporated Multiple Segments spectacle lenses (not yet available in the US), vision therapy for accommodative related dysfunction; and simple behavioral changes to enhance flexibility of focusing.