The filter is intended to be used in the evening in the hours leading to bedtime. In order to gain benefits this filter must be used in complete darkness or in combination with our no-blue light bulbs. Blue light emitted from today’s light bulbs, TV screens, computers and mobile devices suppresses the body’s melatonin production ultimately affecting one’s sleep and overall health.  If our Sleep Glasses are being worn, filters or light bulbs are not necessary. Sleep Glasses are in fact the ultimate solution. It’s important to note that if you need to be up during the night, Sleep Glasses or our blue-free light sources must be used otherwise benefits gained earlier will be negated.