Catarnil Eye Drop is a combination medicine used in the treatment of allergic eye disease. It relieves allergic eye symptoms like redness, swelling, itching, and inflammation of eyes. Always wash your hands before using Catarnil Eye Drop. Use only the number of drops that your doctor has prescribed. If you wear soft contact lenses, remove them before using the drops and wait for at least 15 minutes before putting them back in. If you're also using other eye medicines, wait for at least 10 minutes before using it. Read the leaflet that comes with the medicine for a full guide on how to use the drops and get the most benefit. Don't touch the tip of the dropper or bottle. This may lead to infection. You should use this medicine regularly to get the most benefit and it’s best done at the same time(s) each day. If you want to stop using it, consult your doctor first. The most common side effects include burning sensation in the eye, eye irritation, stinging in the eyes. It may also cause blurred vision, dryness in the eye, and other, rarer effects. If you get any side effects, talk to your doctor. They may be able to tell you ways of reducing or preventing some side effects or suggest another treatment. If your vision is blurred or you have other changes in sight for a time, don't drive until your vision is clear. This is usually a short-term side effect. Do not use this medicine if you are pregnant or trying to become pregnant, or if you are breastfeeding.