I have Lenovo Ideapad Z510 with Intel(R) HD Graphics 4600 and NVIDIA GeForce 840M and I cannot adjust the screen brightness, I think now it is 100%.
Yesterday there was no problems and it wasn't 100% bright. Might be due to an update. Normally I was adjusting the brightness with F11 and F12, they don't work now. Other keys suchs as F7 and F9 work without problem. When I search for "adjust screen brightness" I can see that there is a menu for that but when I click it shows me search results page with all settings, and there is no "adjust screen brightness".
Also I have tried to adjust screen brightness from power options but "screen brightness" doesn't exit there anymore. And I have reinstalled Intel drivers for graphics, it didn't help. What else I can do?