Peripheral Defocus and Myopia Management: A Mini-Review.

Myopia is the most common refractive error in the world, and its' prevalence continually increases. The potential pathological and visual complications of progressive myopia have inspired researchers to study the sources of myopia, axial elongation, and explore modalities to arrest progression. Considerable attention has been given over the past few years to the myopia risk factor known as hyperopic peripheral blur, the focus of this review. The primary theories currently believed to be the cause of myopia, the parameters considered to contribute and influence the effect of peripheral blur, such as the surface retinal area or depth of blur will be discussed. The currently available optical devices designed to provide peripheral myopic defocus will be discussed, including bifocal and progressive addition ophthalmic lenses, peripheral defocus single vision ophthalmic lenses, orthokeratology lenses, and bifocal or multifocal center distance soft lenses, as well as their effectivity as mentioned in the literature to date.