Side effects of using eye drops include worsening of symptoms, especially with prolonged use, and risk of making eye infections and certain eye conditions, such as glaucoma, worse. Eye drops for allergies and eye problems, such as glaucoma, present the risk of side effects ranging from mild eye irritation to eye damage. When using these eye drops, patients should follow instructions on the eye drop package for over-the-counter drops, and should follow doctors' instructions for prescribed drops to ensure eye safety.
Among eye drop users, eye irritation ranks as the most common side effect. For some people, using eye drops produces unpleasant symptoms, including a burning and stinging sensation. Some eye drops make people's eyes turn red, while others experience itching and watering. According to the Glaucoma Research Foundation, several types of eye drops exist for treating glaucoma. These medications, however, bring a risk of negative reactions. Some, like prostaglandin analogs, increase the flow of fluid from eyes. While producing few systemic reactions, analogs may change the eyes themselves, including changing color of irises and affecting eyelash growth. Carbonic anhydrase inhibitors, another prescription eye drop class, might cause eye irritation, stinging and burning, and produce systemic effects in pill form. As with other medications, the severity and type of symptoms from using eye drops varies among individuals, and depends on other factors, such as use of other medicines.