Dimming or turning out the lights seems like a good idea for a magic trick or scary story, not surgery.However, performing surgery in the dark is actually what surgeons are forced to do for some procedures, where darkened operating environments are optimal for utilizing fluorescent compounds that highlight specific tissues — think cancer — in patients’ bodies.OnLume, a Madison company founded in 2015, is aiming to change that with technology designed to shed new light on complicated surgical procedures.