Lux meter - Voltage range problem measurment
Your approach isn't a great idea for this application. You almost never see it that way in instrumentation design. 

What you want to do is implement a series of sensing scales. That is you have a system that can work over different light intensity ranges and you switch between them to effectively increase your dynamic range (range of light input you can handle) without increasing your voltage range. As a bonus you can get higher sensitivity from the decreased power supply noise (greater CMRR) if you're careful.

Here is an architecture that I helped develop:



The module looked like this:



It could go from complete darkness to well beyond 10k lux with accuracy better than the commercial meters of its day on a single 5V rail. You can find a number of papers by me and others on the project here.