A year-long investigation has resulted in the arrest of a Washington mother who is accused of putting eye drops containing bleach into her young daughter's eyes. Now, the mother is facing criminal assault charges for allegedly blinding her daughter, who has since been living with her father.

According to police reports, the investigation began in May 2011 when the 14-month-old girl was airlifted to Harborview Medical Center in Seattle in order to be treated for a serious head injury. While treating the head injury, which hospital staff believed to be the result of abuse, the doctors began to suspect that the girl also had an eye infection.

When doctors asked about the eye infection, the mother reportedly said that her daughter's eyes had been swollen shut for about a month after she had received a scratch on her eye while playing in a barn. The mother stated that the girl had been given antibiotics and eye drops, which she had brought to the hospital with her, to treat the eye infection.

Hospital staff inspected the eye drops and allegedly noticed a "foul odor." The drops were sent to the Forensic Chemistry Lab of the Food and Drug Administration, which reportedly determined that the eye drops contained bleach. The mother told police investigators that the bleach was the result of the dropper being cleaned with the substance, but the lab reportedly found that this was not possible based on the damage to the girl, which included blindness in one eye.

Now, a year after the alleged incident, the 29-year-old mother has been arrested and charged with assault. We will continue to update our blog as this case develops.

Source: CBS News, "Wash. mom Jennifer Mothershead accused of putting bleach into her toddler's eyes," May 1, 2012