I've seen a lot of 1911 pistols, where the back of slide, ejector, extractor, rear sight, front sight, and the top of slide are serrated to prevent glare. . . and then there's this. Lone Wolf Distributors is taking the opposite approach, and is Titanium Nitride plating Glock slides. The cost for refinishing a slide is $105. You can get them to do sights for you too, if you want.
Titanium Nitride coating does actually make sense for some firearm parts, and offers many of same benefits of Nickel Boron coating, as made famous by FailZero. However, and it's a big however, Titanium Nitride coating a pistol slide and/or sights, is probably not a good idea, unless perhaps you are a drug dealer, and you surround yourself with a dozen well-armed thugs at all times.
Sorry, LWD, for beating up on you, but this is kind of goofy, at best.