(WCNC/NBC News) A South Carolina woman has been charged with murder after admitting to investigators that she poisoned her husband using over-the-counter eye drops.

York County Sheriff's deputies say Lana Sue Clayton added eye drops containing tetrahydrozoline to her husband's drinking water over a three day period.

Stephen Clayton was found dead in their Clover home on July 21st. An autopsy later revealed elevated levels of the drug in his system.

York County deputies said 52-year-old Lana Clayton confessed to investigators after an autopsy uncovered a high amount of tetrahydrozoline in her husband's body.

The chemical is found in over-the-counter eye drops such as Visine.

Arrest warrants and the statement from deputies didn't give a motive for the alleged poisoning.