Gene therapy (and CRISPR) is ultimately going to eliminate most if not every ailment/issue/genetic problem that we have, including aging and eye problems. Very thankful we are reaching the point where we can go into our cells and fix ourselves.
That was the plan from the start, no? I was pretty disappointed to learn that most drug research is essentially mass testing all kinds of molecular agents that happen to show some beneficial effect for a problem at hand. It seems just too simple a method.
However, don't downplay the importance of the shotgun approach. In the broadest sense, it gave us Viagra for ED (common reported side effect in an unrelated trial), Aleve (intended to be a hangover treatment you'd take the night before), ...
With computer and analytical modeling, it's a much easier process to identify a problem and reverse engineer a treatment.