Topic is very good

  • lorna Oct 30, 2018, 12:19 AM

    So, the thing to remember is that when we say "blue light" that isn't a standard measurement - meaning that many people use a slightly different definition. It's literally a spectrum, and to speak with certainty about how much is being blocked, we have to define the range first, of both the filter and of the light source.

Log in to reply