Dim light melatonin onset (DLMO) is a useful marker for assessing the circadian pacemaker. It is also used to assess circadian rhythm disorders. One of the main reasons why DLMO is important is that it can determine when to expose or shield from light to delay (shift later) or advance (shift earlier) the circadian rhythm. A common scenario these days is sleep deprivation due to staying up too late. In this scenario a person might complain of feeling it is very difficult to get out of bed in the morning (maybe even pushing snooze several times) and yet is not going to sleep early enough to allow for a full 8 hours of sleep because they don’t feel sleepy at bedtime. This person may be on their phone, computer, or watching TV in the hours before bedtime. It becomes a vicious cycle. Before the invention of the light bulb, 12 am was the middle of the night (which is why we call it midnight) but now it is not uncommon for it to be the beginning of the night (bedtime) for some. There is no doubt that electricity is a major factor. One very easy environmental modification you can make to help reduce this effect is to change your bedside light bulbs to amber colored bulbs that filter out blue light, since that is most potent for shifting DLMO. In addition to the benefit in sleep, I find the hue very relaxing, almost like the color of a candle. There are lots of options on amazon and other retailers online. Have you tried amber colored bulbs?