I'll argue that. If I can't identify my target I'm not shooting. That requires illumination and enough that the blades outline and my sight picture is visible. Now I have a tritium brightly colored dot on my front sight post that can blur and obscure instead of black crisp outlines of my irons. So again, it may be an upgrade but it's certainly a modification.If you replace a set of iron sights with tritium night sights, that's a modification and an upgrade. The modification is implicit in the term "upgraded."