A South Carolina woman was sentenced Thursday to 25 years in prison after she poisoned her husband by putting eye drops in his water for days.

Lana Sue Clayton, 53, pleaded guilty to voluntary manslaughter and tampering with a food or drug after she admitted to giving her husband, Steven Clayton, drinks laced with Visine.

Steven Clayton died in July 2018 at their home in Clover after three days of poisoning, prosecutors said.

The woman said her husband was abusive, and she meant to "make him uncomfortable" but not kill him.

"I did impulsively put the Visine in Steven’s drink," she said in court. "I never thought it would kill him."

Prosecutors said Lana Clayton knew the Visine would kill him. The couple lived in a $1 million home and the husband had more than $1 million in other assets. Prosecutors said the woman wanted to inherit the money.

Poisoning from Tetrahydrozoline – an ingredient in over-the-counter eye drops – can induce comas, stop breathing, blur vision and cause seizures, according to the U.S. National Library of Medicine. Children who swallow even 1 to 2 milliliters can suffer “serious adverse events." It's added to eye drops and nasal sprays to reduce redness.

Contributing: Ashley May; The Associated Press.