A female inmate in California ripped out her own eye and swallowed it in her cell after prison guards ignored her screams for four hours.

The gruesome ordeal took place last year at the California Institution for Women in Chino.

The woman, who has not been named, had been screaming every 15 minutes for at least four hours before she got on the floor and tore out her eye.

She had already eaten her eye by the time guards rushed into her cell.

The woman, identified only as Inmate Patient X, was not being given medication even though she had been identified as 'psychotic'.

The ordeal was detailed in a recent report obtained by the LA Times that is critical of mental healthcare in California prisons.

Chief psychiatrist for the state's prison system, Dr Michel Golding, wrote the report and said vulnerable inmates are allegedly not being cared for properly.

The inmate who tore out her eye was evaluated by a psychologist but a psychiatrist was not brought in to administer any drugs.

Doctors said in the aftermath and she had shown signs she needed immediate medication.

'The tragedy is that any competent psychiatric physician or general medical physician would have medicated the patient, and likely the patient's eye would still be in her head had that happened,' Golding said in his report.

The California Department of Corrections and Rehabilitation issued a statement slamming Golding's report.

'The department strongly disagrees with this individual's allegations, and looks forward to a fair and thorough review and hearing of all the facts,' a spokeswoman said.

'We have worked closely with lawyers representing prisoners, as well as the court appointment monitors, for many years to improve the mental health of inmates, and our dedicated and well-trained staff will continue to provide appropriate care and treatment.'

Golding's report was included in federal court documents linked to a lawsuit that is arguing that psychiatric care in prison is a constitutional right.