Spectacle lenses for control of myopia progression in children.

Many new optical treatments have been developed recently to slow the progression of myopia. Most of these are based on theories of how myopia develops, such as poor accommodation, the type of peripheral refraction and image contrast (contrast modulation). Optically related treatments include spectacle lenses, contact lenses, orthokeratology, light therapies, more outdoor time, better interior lighting, indoor illumination, pharmacological intervention (through pupil and accommodation effects) and combination therapies. Current myopia-control spectacle lenses are described, including progressive addition, multisegment, annular cylinder, diffusion optics technology and concentric bifocals. Background is provided and a critical eye is passed over some of the designs. Short-term (12-month) efficacies for both axial length and myopia reduction in myopia-control spectacle wear, relative to single-vision lenses, are about 50%, as compared to 50%, 60% and 80% for contact lenses, orthokeratology and red-light therapy, respectively. Spectacle lens treatments for myopia control are safe, valuable tools in clinical practice. Further laboratory and clinical studies should help to clarify the nature of the mechanisms of action and improve efficacy.