In {HEAD ~ some embodiments}, the optical properties of {TAIL ~ at least one lenslet} are tunable 
In { HEAD ~ some embodiments } , the optical properties of { TAIL ~ at least one lenslet } are tunable
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH