There must be a prism in there or something to help gather and distribute light, but when looking through the peep, it is visible in very low light...surprisingly so really. Nothing special or feature-laden about the top of the disc that you view when just holding it. I have an older version of this compass (nothing has changed about it) and I don't really use it but comparing to my standby M3-D (now just M3), the KB does excel in low light, as long as the peep design is still useful for your application (i.e. if you can't see objects in the distance - open areas or not - then it may not be any more useful than another compass design. You will be able to see your bearing in the peep but maybe not direct it to a landmark).