Optihist Cromz Eye Drop is a combination of two medicines. It is used in treating allergic eye reactions. It relieves itching, discomfort, and irritation caused due to allergy. It also has antibacterial action that prevent infection of the eyes. It also reduces inflammation (redness and swelling). Optihist Cromz Eye Drop is strictly advised to be used only in the eyes. Use it in the prescribed dose and duration. Apply it only on the affected eyes. You must wash your hand before administering the medicine. Do not use it more than the recommended dose. The medicine should not be stopped suddenly without doctor's consultation. It is generally safe, but it may sometimes cause irritation, tingling sensation, discomfort, and pain in the eyes. These effects are mild and go away in some time. However, if these effects persist, you should consult the doctor immediately.