Note that you can automatically adjust the display colour temperature to match the time. I use this and it makes a huge difference. On Linux use Redshift. On

Note that you can automatically adjust the display colour temperature to match the time. I use this and it makes a huge difference. On Linux use Redshift. On other operating systems use f.lux. http://jonls.dk/redshift/ http://jonls.dk/redshift/ http://stereopsis.com/flux/ http://stereopsis.com/flux/ When you toggle/disable them you realise just what a difference it makes.