In 2000, a study published by George Fulk and colleagues at the Northeastern State University College of Optometry in Tahlequah, Oklahoma carried out a well controlled, randomized clinical trial to assess whether bifocal spectacles can slow myopia development in a subset of patients who were esophoric and believed to exhibit significant lag of their accommodative systems. Their group found a 20% reduction in myopia progression in the bifocal treatment group versus the control group using single vision spectacles.
The children in the COMET (2003) and COMET2 (2011) studies study, with much larger study populations than the Fulk et al study, were randomized to either single vision or progressive addition lenses (PALs). While statistically significant levels of slowing myopia progression in the treatment group (14% reduction in COMET, 24% reduction in COMET2), clinically meaningful reductions in myopic progression were not obtained.
Related Products that do provide clinically significant levels of slowing myopia progression: