Most people are completely unaware that the sources of artificial blue light are everywhere; in today's modern world, you simply cannot escape it. All modern devices which have a light source will produce some amount of blue light even if it doesn't appear to look noticeably blue.
In fact, all artificial, electric-powered devices which produce a light source will emit blue light to varying degrees, even if it doesn't look blue.
The most common sources of artificial blue light include:
Tablets such as iPads
Smartphones
Monitors from computers and laptops
LED and plasma TV screens
Fluorescent lighting in offices and stores
Conventional LED lighting in houses
The light inside your fridge