Remove C3. To measure the light, you have to know the voltage (the DC voltage).
Why is there a feedback with Q3 ?
The voltage drop over the diode D11 should activate Q3, that is not a good design.
The voltage drop will also make the leds less bright.
Can you remove D11 and Q3 ?
Why do you have 5 leds in a group? Can it be 6 ? Now you have to tune the resistor so they will be more or less equally bright. That is inconvenient.
You can use transistors to drive the leds, but there are special chips for drivers (8 channels in a chip, as in the ULN2803) and even special led driver chips.