They work
Working shift work has many health implications, one being disturbed sleep. For many years I haven't been able to use my laptop after 7pm due to blue light affecting my ability to get to sleep; plus recently I've been waking up in the early hours and not being able to get back to sleep.
So did a little research and decided I had little to loose but plenty to gain and bought the NighFall glasses. They worked from the first evening! I can now use laptop and sleep well. Would definitely recommend these glasses to anyone with similar issues. Yes it is a little strange watching the TV but it's a small price ot pay for a good nights sleep.