Does nothing for mirage that ive ever noticed. Only way to reduce mirage is to reduce magnification, even then if conditions are right you can get mirage with zero magnification.
My preference when its cheap enough are tenebrex killflash covers
"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith