想問點解眼藥水有HCI?

Yes , isolated HCl is very acidic but in eyedrop , it is only few % & the active ingradient is a chemical cpd combined called so & so Hydrochloride , e.g.Phenylephrine Hydrochloride . The HCl is combined with a chemical so it is not acidic & corrosive any more !

因為酸與它的鹽會生成緩衝溶液，緩衝溶液是加入少量酸或鹼，pH只有輕微改變。
眼藥水也是緩衝溶液。