The 9th Plague. The Darkness Trilogy

The world didn't end with fire or ice-it ended with darkness. In a top-secret Silicon Valley lab, military scientists have created the ultimate battlefield weapon-nanobots capable of infiltrating human hosts and shutting down their vision. The project, known as Blindside, was meant to be contained. It was never supposed to leave the lab. But technology doesn't always follow orders. When a containment failure allows the nanobots to escape into the world, the infection spreads like wildfire.
First through Washington, D. C., then across the entire planet. Within days, pilots lose control of planes, drivers cause pileups, entire cities descend into blind chaos, and governments collapse overnight. Now, in the midst of global disaster, two survivors fight to escape the growing darkness:Phoenix Walker, a former Army Ranger locked away for a crime he didn't commit, is the only sighted person left in a maximum-security prison that's turned into a war zone.
Dani Tyler, an 11-year-old girl, must take care of her blind mother while surviving a city filled with desperate and dangerous people. As the world crumbles around them, a terrifying truth emerges: there is no cure for the Wonder Bugs, and the scientists responsible never finished the failsafe. Now, the last remnants of civilization are racing against time to find a solution before the entire world is lost to darkness forever.
A gripping blend of techno-thriller, dystopian sci-fi, and survival horror, The 9th Plague is perfect for fans of Michael Crichton, The Stand, World War Z, and The Day of the Triffids. If you love high-stakes thrillers, scientific disasters, and gritty survival stories, this is the book you've been waiting for.