Under-correction for left eye?

I'd need to see the results of your left eye measurements to know for sure, but you may benefit from an enhancement. I perform these not before 3 months and when the vision has completely stabilized.Your left preop prescription was fairly large, and this does increase the chance of needing enhancement by a small margin. Slight devistions from intended results are generally caused by slight variability in tissue response to the laser rather than measurement errors.

The difference in clarity can be overcorrection, undercorrection, a displaced flap, irregular astigmatism, amblyopia among other things.  If you were correctable to 20/20 pre op, you should be correctable to 20/20 post op unless you have irregular astigmatism.   If you look through a pinhole and can see clearly, the problem is likely a residual refractive error but can be irregular astigmatism (an irregular surface) as well.  Only by a detailed examination can the cause be determined.