Final answer:
An enzyme is added to ophthalmic anesthetics to enhance their effectiveness. Carbonic anhydrase is used to inhibit the formation of excess fluid in the eye for treating glaucoma.
Step-by-step explanation:
An enzyme is added to ophthalmic anesthetics to enhance their effectiveness. In particular, the enzyme carbonic anhydrase is used to treat glaucoma by inhibiting the formation of excess fluid in the eye. By competitively inhibiting carbonic anhydrase, the enzyme acetazolamide prevents the accumulation of fluid, reducing intraocular pressure.