If you have a Sony Vaio the following link may be of use.
Also this link may be of benefit
Apologies if you already know about the above
Firstly, I assume that you tried the following "fix" which was in the first link I sent and it didn't work
Launch VAIO Control Center (Windows Key + Q then type in VAIO control center)
Under Display uncheck adjust brightness settings automatically
Reboot your machine
Did you go to the Sony support page and find out info about driver updates for your particular model? I was only generalising when updates might be available because I didn't know your exact model or OS.
So your options as I see it are:
1. Find out how long before Sony provides driver updates and wait until then, if you can put up with it that is.
2. If you can't put up with it roll back to Win 7 (as long as the 30 day expiry period in still valid). If it has been more than 30 days unfortunately you can't roll back. You can always go back to Win 7 after the 30 days with a fresh install but that would be rather extreme.
It is my understanding that you can roll back to Win 7 if within the 30 days and then still upgrade to Win 10 later on, when drivers are available, at no cost. My info on this might be wrong and you should double check.
Win 7 is still being supported until 14.1.2020 so it is not that it is disappearing anytime soon.
If you like Win 10 you might want to hang in there (if Sony comes thru soon), after all it is Microsoft's latest OS and after the debacle of Win 8 I'm sure that it will be a good OS. History seems to show that they get every 2nd OS right. (Win98+, Win Me-, Win XP+, Vista-, Win7+, Win8-)