Swan plant's toxic sap blinds Northland man

Bob Warman went blind in both eye temporarily because of swan plant sap. One eye is still in recovery mode nine months later. Photo/ John Stone

Bob Warman isn't afraid of hard work in the garden.

Nearly nine months ago he was pruning swan plants on a hot day.

It was when he wiped the sweat out of his eyes with the back of his arm that the white sticky sap of the swan plants was smeared across his eyes.

"I knocked the tops off the swan plants.... they were getting a bit high. I do recall seeing all the white stuff on my arm but didn't take any notice of it."

Three hours later he could feel a stinging sensation in his left eye. He rinsed his eye with water and used some eye drops, but didn't think too much about it.

The sap of swam plant is very toxic.

Then at 4.40am Mr Warman woke to find he couldn't see. He likened it to trying to look through a foggy shower door. "I had a moment of panic. I made a cuppa and sat down."

He said he couldn't see his phone to call for a taxi and he was unable to rouse his next-door neighbour to help him. So he walked from his Morningside home to White Cross on Bank St in central Whangarei.

"I had a bit of peripheral vision so I had a bit of an idea of where I was going".

But it was the voices of children going to school he used as his main guide.

"I found out what it's like to use the buzzers at the intersections."

Months later he has regained sight in his right eye but scarring has left vision in his left eye far from the perfect vision he previously had.

An opthamologist - a doctor who specialises in eye and vision care - who saw Mr Warman was not surprised the swan plant sap had caused the damage as it is very toxic.

Mr Warman wanted to share horrific experience so those with the plants were aware of the potential risks.

"Every one I tell about what's happen [people] aren't aware of how toxic it is. I just want parents to know so they can just watch their children as they are very popular when it comes to monarch butterflies and learning about the life cycle."

The swan plant is a food source for the caterpillar of the monarch butterfly. The life cycle of the monarch butterfly is the main reason the swan plant is present in preschool centres as children can trace the changes from egg to caterpillar to chrysalis to butterfly.

The New Zealand National Poisons Centre website says swan plants are toxic, and swallowing even a small amount could be a problem. Ingestion of the plant material can affect the heart, breathing, central nervous system and the stomach.

The site says because of the educational benefits of teaching children about the life cycle of the monarch butterfly, swan plants are not on the Landcare Research list of plants that should not be grown or tolerated in New Zealand preschool centres.

"Although it is a toxic plant, swan plants can be grown in childcare centres or homes with small children, providing supervisors are aware of the toxic nature of the plant, and take all necessary precautions to prevent poisoning from occurring."

The site recommends if the sap is swallowed people immediately seek medical advice from a doctor. It is not necessary to give any fluids, and do not make the person vomit.

If on skin flush the exposed area with lots of water and seek medical advice. If in the eyes flush the eye with room-temperature water for at least 15 minutes and seek medical advice.