Zymar is a fluoroquinolone antibiotic. It does not have any addictive effect but still do not use it without a doctors prescription. It is a ophthalmic drop. Some serious side effects includes severe swelling, burning, redness, or discomfort in or around your eye; eye pain, vision changes, increased sensitivity of your eyes to light; signs of new infection, such as drainage, crusting, or oozing of your eyes or eyelids; or the first sign of any skin rash, no matter how mild. Less serious side effects includes mild itching, burning, redness, or irritation;watery eyes;puffy eyelids;headache; or unpleasant taste in your mouth after using the drops.