Well there are several topics here: first, it is not true that people thinking about visual performance will find the right schedule for non-visual (circadian,

Well there are several topics here: first, it is not true that people thinking about visual performance will find the right schedule for non-visual (circadian, alertness). The two are simply different concentrations, and we have chosen to focus our research and work on non-visual responses. Treating sleep-maintenance insomnia is often done by increasing light levels at night to move rhythms later, and seasonality often requires different patterns of light based on the time of year. This is one of the reasons we have been asking people not to copy what we said in 2009 - some people need more light at night during the winter, not less, and timing needs vary greatly. Our core audience for f.lux is younger people, and on average they need less light at night - the normal distribution of chronotypes has a very long tail in the direction of night owls, and their timing tends to be most at odds with society's requirements for wake times. So I would say the product as it is today tends to be a better fit for the night owl half of the distrubution, and not extreme early types. But our main area of study is to generalize these schedules and lighting changes to be "right" for nearly everyone. It is rather difficult work, and you have to study the effects over years.