Natalie Farrell, 27, from Dundee, told the High Court in Edinburgh that she did not realise what had happened until a friend handed her eye to paramedics.
Francis Murphy, 26, denies two charges of attempting to murder Ms Farrell at Dalfield Court in the city.
He has already admitted pulling out her eye on 26 May this year.
It is alleged Ms Farrell suffered two separate bids to kill her that day after she ended her ten-year relationship with Mr Murphy.
She told the court that her former partner had said if he could not have her, no one else would after she told him she had found a new partner.
She told prosecutor advocate depute Iain McSporran that describing how Mr Murphy took out her eye was difficult to put into words.
She added: "I have lost half my sight. That is me disabled for life now."
'I am taking your eye out'. He had the hook or the coat hanger and he was trying to get that into my eye
The trial heard that Mr Murphy entered the home of Ms Farrell and her partner Paul Stanton at Dalfield Court after they mistook him for another visitor and buzzed him into the property.
She said she was shocked and nervous when Mr Murphy came in.
"He was under the influence of drugs and also heavily intoxicated with drink," she claimed.
She said he sat on the bedroom floor and demanded a roll-up cigarette, which she gave him.
"I seen a metal thing in his hand. It was like a paper clip opened out."
She said he then began attacking Mr Stanton with the metal object forcing him to run from the flat to get help.
She said Mr Murphy then turned to her and said: "'I am taking your eye out.' He had the hook or the coat hanger and he was trying to get that into my eye."
He then tried to get his thumb and two fingers into her eye, she said, then put his hands round her throat and strangled her until she blacked out.
Mr McSporran asked if she felt her eye being pulled out.
Ms Farrell replied: "Because of the adrenalin and the fear I didn't feel pain at the time. And as soon as he done that he strangled me and I went unconscious.
"I only felt pain when I woke up in hospital."
Ms Farrell said her right eye was hanging by the optic nerve as she fought back, hitting Mr Murphy over the head with a cup to gain enough time to run from the flat.
She told the court she then hid on a balcony after fleeing the flat but that Mr Murphy saw her and began pulling her by the legs towards the rail of the balcony.
She said he then made a move as if to brush hair from her face.
"See how your eye dangles on the optic nerve. He wasn't pulling the hair off my face, it was the optic nerve," she said.
"They found my eye lying at the bottom of the balcony."
She said when her friend found her eye she asked paramedics: "Any chance you can save it?"
"Don't get your hopes up, darling," she was told.
Solicitor advocate Iain Paterson, defending, said: "Murphy has no recollection of what happened in your flat."
The lawyer continued: "You have sustained a terrible injury. Murphy accepts that he inflicted that terrible injury on you."
The trial before Lord Brailsford continues.