In the absence of any reply, here or at
https://www.raspberrypi.org/forums/view ... 3#p1550683, I'd be wanting to distinguish between "hazy" as in out of focus, "hazy" or "washed out" as in black not being fully black, and "washed out colour" as in deep red being only pinkish, deep blue being grey-blue, etc.
The first could be the lens but not the sensor.
The last could be the RGB filters on the sensor pixels being degraded.
Don't know about the middle.
Also, I don't know about the IR filter.