The ornamental design for an adjustableopticalassembly, as shown and described.
FIG. 1 is a front perspective view illustrating an adjustable optical assembly, with an example of a pair of glasses connected thereto illustrated in broken lines;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a side view thereof;
FIG. 5 is an opposing side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines shown in FIGS. 1-7 are for illustrative purposes only and form no part of the claimed design.