Patna: For many, Holi is incomplete without a play with colour balloons. It's fun when you hit a person with colour balloons drenching them in colours, but it can also trigger serious eye injuries, warned doctors on the eve of Holi.

"When you hit someone with colour balloons, it is like hitting someone with a tennis ball," said ophthalmologist and director of Sanjeevani Eye Hospital and Research Centre, Dr Sunil Kumar Singh. "If it wrongly hits the eye, it can cause retinal edema (abnormal accumulation of fluid in certain tissues) and also retinal detachments, a disorder in which the retina separates from the layer underneath. It is a medical emergency."

Singh said if the toxic chemicals in the Holi colours gets into one's eye, it can also cause eye infection. "It can cause redness and discharge from eyes. Such patients are prescribed anti-biotic eye drops. Also, if glass powder, which is usually present in artificial colours, gets into one's eyes while playing Holi, one should avoid rubbing. It can cause abrasion of cornea. The best thing to do in such a situation is to wash your eyes continuously with cold water for next few minutes," said Singh.

Singh offerer a few tips on how to protect one's eyes from such injuries. "Wear big-frame glasses to protect your eyes," he said.

There was also a word of caution for those who drink bhaang (cannabis)-mixed thandai, a special drink prepared with milk, dry fruits and other materials. "If adulterated bhaang is used in thandai, it can not only temporarily damage brain cells, but sometimes also cause permanent damage," said Diwakar Tejaswi, a physician. "Adulterated bhaang can also cause heart rate irregularity. It can increase blood pressure among other problems. Also, even if bhaang is not adulterated but mixed beyond the limit in the drink, it can cause arrhythmia (irregular heartbeats), hallucination and also alter the respiratory process."

Diwakar said the artificial colours in the market have heavy metals mixed in them which can affect liver, kidney and other body organs.

"It can cause skin allergy and irritation among other skin-related problems while if one consumes it by mistake, it can also affect liver, kidney and other organs. While the black colour in the market may contain copper oxide, the red colour contains other heavy metals, like mercury, while silver colour may contain aluminium bromide.

While on theo one hand, playing with these synthetic colours can cause skin and other health problems, the synthetic colours also affect our environment as they reach our river through the drainage system," Tejaswi said.

Talking about precautions one should take while playing Holi, he said: "Apply moisturiser on skin or oil and also oil your hair. Play with herbal colours."