Just had meprolights put on my sr9c and my cz75b. Of course you can't see glowing sights in daylight, but I've had a chance to try them out at one of the local rages where the lanes tend to be dimly lit. Oh boy they do light up. A great help in focusing on the front sight. I have not fired them in darkness yet, but in a pitch dark room, the sights are very clear. A good investment I think.