It is used to prevent the itching, inflammation and watering eyes. It reduces the redness, swelling and congestion in the mucous membranes of the eye. It helps to ease the eye's symptoms caused by an allergy.

Do not use Cromoglicate, Tetrahydrozoline:

Do not use If you are allergic to any of the other ingredients in this medicine.
In addition, it should not be used if you have the following conditions:

• Acute attack of bronchospasm
• Children below the age of 6 years
• Hypersensitivity
• Infants below 2 years of age
• Pregnancy

Warnings and precautions:

All eye drops can cause a short-term blurring of vision when first used so you should wait until your eyes are clear before driving or using machines.
If you wear soft contact lenses. Do not use the drops while your contact lenses are in your eyes. Wait 10 -15 minutes after using the eye drops before putting your lenses back into your eyes. 
Possible side effects
Stop using the product and seek immediate medical attention if you develop throat tightness or swelling of the eyes, face, lips or tongue, feel faint, or have difficulty breathing. Stop using the product if you develop hives or itching of the face or body.