Dr Cathleen Fedtke, Dipl. Ing. (FH), PhD, FAAO
BHVI
The use of the spectacle lenses for myopia management dates back more than 30 years ago, when bifocal spectacle lenses prescribed to children with near-esophoria showed a reduction in myopia progression.1,2
Since then, several spectacle lens-based approaches have been assessed based on the two main theories of myopia development and progression: the Accommodative Lag and the Peripheral Hyperopic Defocus theory.
The Peripheral Hyperopic Defocus theory is based on the findings that in myopic eyes, peripheral refraction profiles are relatively hyperopic; hence, it was hypothesised that both kinds of hyperopic blur signals could be a trigger for eye growth.
While the Accommodative Lag theory presumes that an insufficient amount of accommodation during near work – as reported in myopic children – causes retinal blur. The Peripheral Hyperopic Defocus theory is based on the findings that in myopic eyes, peripheral refraction profiles are relatively hyperopic; hence, it was hypothesised that both kinds of hyperopic blur signals could be a trigger for eye growth.
Optical intervention methods for both theories therefore aim to reduce hyperopic defocus, either centrally during near work or in the peripheral visual field.
