Answer:
Older adults should not spend daytime outdoors without sunglasses, nor should they drive their vehicles without sunglasses during full daylight.
Explanation: The clause Older adults should not spend daytime outdoors without sunglasses is an independent clause. The clause should they drive their vehicles without sunglasses during full daylight is also an independent clause. When two independent clauses are joined by a coordinating conjunction (and, but, or, nor, for, so, yet), add a comma before the coordinating conjunction.