Is it possible to have an allergy to acrylic cataract lenses they put in surgically to correct cataracts?

Probably not: "allergic reactions" do not occur to either silicone or acrylic intraocular lenses. Very rarely people have issues where the lenses need to be removed or exchanged for a different material (silicone for acrylic or vice-a-versa) but this is exceedingly rare. In these situations there are usually other factors in the eye contributing to the need for exchange and not an allergic reaction.

Probably Not: Although it is theoretically possible to be allergic to almost anything, acrylic cataract implants are virtually inert and totally biocompatible. This means they don't cause any reaction from your body. After having done thousands of cataract implant surgeries I have never seen one that looked like the person was allergic to the acrylic implant.