Irritants

• When there is something in the eye that shouldn't be there, tears are released to get rid of it. Onions are a common eye irritant but any fume could cause the eyes to water.
  
  

Injury

• Any type of scratch on the surface of the eye can make it water. A grain of sand or some dirt could cause this.
  
  

Conjunctivitis

• Conjunctivitis is a common eye infection characterized by tearing, redness and white, yellow or green discharge from the eye.
  
  

Entropion

• Entropion is a condition in which an eyelid is turned inward or outward. Some of its symptoms are watery, sore or red eyes, eye irritation and corneal scratches.
  
  

Cold

• Watery eyes, sneezing, a stuffy nose and a sore throat are all symptoms of a common cold.
  
  

Allergies

• Eye watering is one of the body's ways of defending itself against unfamiliar substances.