There are 828 blind people now, 267 of them being blind in both eyes. They are mostly farmers or women and young girls employed to peel the onions after harvest.

The farmers use parathion, an insecticide that is banned or restricted in many countries, to protect their onions from insects.

Can Tho-based eye doctor Nguyen Thanh Liem said if the insecticide comes into contact with people's eyes, it could cause inflammation or ulceration of the cornea leading to blindness.

Farmers said they use a mixture of 40 kilograms of soil and four kg of the chemical to preserve a ton of onions, failing which the onions would be eaten by ants and worms in just a week.

They said they know that the chemical is dangerous, but have never been taught a safer way to preserve the onions. They used to use DDT until it was banned.

Local doctors warned the situation is likely to worsen. Around 300 people are treated for eye problems or operated on every year now, they added.

Source: Thanhniennews