jetskihernia f.lux is only addressing the issue of being exposed to blue light. Even though it tones down the amount of blue you are still being exposed to some. Gunnar glasses block 65% of blue light from digital screens, but they also address the issue of digital eyestrain which is the adverse side effects (headaches, blurry vision, dry/irritated eyes) that come from close distance screen viewing for long periods of time.