&gt; <i>If you believe using your phone late at night is harmful to you at all</i><p>If you’re asking about me personally, I don’t use a smartphone at night. I thought we were talking about what actions smartphone vendors could take to help their customers’ health.<p>&gt; <i>Even with these apps a phone will still emit a large amount of blue light and having the light source so close to my face I still notice it disrupts my sleep.</i><p>If you use f.lux on a Mac, you can make it incredibly orange almost completely blocking out the &quot;blue&quot; channel on the display. It also includes a &quot;darkroom&quot; mode which inverts the display colors and turns black text on white into red text on black.