It has been suggested that during our evolution our bodies automatically react to light as the sun sets and prepares our body for sleep before you actually fall asleep. As the sun goes down it contains less “blue light” and blue light is one of the first colours in the spectrum. Have a look at the chart below and see how Blue, Indigo and Violet has the lowest wavelength. This means the light carries more energy and it is that which the eye and brain use to determine the time of day.

Visible spectrum diagram

The problem is that in artificial light, there is a lot of blue light, especially from tablets, computers and smart phones. If you use these right up until you sleep then you are asking for disturbed sleep patterns. That said, some people need to work on screens in the evening or before bed. As such, you might want to try some safety glasses that filter out Blue Light. They are designed for working outdoors, especially by water where blue light is a problem but of course you could use them for helping you sleep!

Here is one we’d tend to recommend since it used the Blue Light Filter lenses and also only weights 21g.

Contour (ESP Lens)