So, you are looking for a 1 or 0? Put the CDS cell in series with a resistor to VCC. If you put the CDS to ground, you will get a 0 with light, if you put the resistor to ground, you will get a 1 with light.
You might be needin' some really bright lights there. I get a 32k reading shining a 100w lamp on it. To get proper logic signals i think you would need to have at most 15k on the CDS