University of Arizona
The lenses in Night Swannies were found to be among the top performers in lenses that block sleep-disrupting light, in a study conducted by the University of Arizona.
Dr Michael Grandner, Director of the University's Sleep and Health Research Program tested 50 lenses from a variety of brands for their effectiveness in blocking short-wavelength light that suppresses natural melatonin production.
Dr Grandner says that Night Swannies "have managed to combine effectiveness at filtering sleep-disrupting light while also allowing in non-sleep disrupting light, striking the right balance between sleep benefits and wearability and thus allowing for comfortable reading, screen viewing and night time activities without appearing too dark."
You can read more about this study here.