SINGAPORE - For close to 1½ years, a man sexually assaulted his stepdaughter regularly, even when his wife lay asleep on the same bed.

The girl, who was eight when the abuse started, would cry when she had to return from her weekend stay with her biological father to the flat she shared with her mother and stepfather.

Her father, who thought she merely wanted to spend more time with him, eventually found out about the abuse after her cries became hysterical on one occasion.

On Friday (July 12), the stepfather, a 42-year-old canteen helper, was sentenced to 15 years' jail and the maximum 24 strokes of the cane.

He pleaded guilty earlier this month to a charge of sexual assault by penetration of a minor and two charges of molestation of a minor. Another seven molestation charges were taken into consideration.

In sentencing, Justice Valerie Thean rejected his lawyer's plea for judicial mercy on the basis that the man was legally blind and diagnosed with glaucoma, which would cause him undue hardship in prison.

The judge said there were no exceptional circumstances to warrant the exercise of judicial mercy and she has been assured that the prison authorities would be able to manage his condition.

The parties cannot be named due to a gag order to protect the victim's identity.

The court heard that the girl's parents divorced in 2009, with the mother getting custody of all four children. The father, who remarried, was granted access to the children on alternate Sundays.

After the mother remarried in 2013, the victim and her siblings lived in the same flat with their mother, the accused, the couple's two children, their mother's parents, their mother's grandaunt and a domestic worker.

The victim slept in the same room as her mother, stepfather and step-siblings.

In January 2015, when the girl was in Primary 3, the man began sexually abusing her, even though his wife slept in the same room and often on the same bed.

He started touching the girl over her clothes but progressed to more intrusive acts, including oral sex. The assaults became more frequent when the girl's mother became pregnant.

The girl either pretended to be asleep while he violated her or resisted by turning her body away.

On Oct 17, 2016, she cried hysterically and refused to enter the flat when her father was taking her and her siblings home.

She revealed the abuse to her father after he sensed something was amiss and took her downstairs.

Her father made a police report the next day. He took her to see a counsellor, who noted in a report that the girl had nightmares about the accused and was mentally disturbed.

Deputy Public Prosecutor Kavita Uthrapathy sought at least 18 years' jail and 24 strokes of the cane.

"The victim will never be able to regain her lost childhood or the innocence the accused had so callously defiled," she said.

The accused's pro bono lawyer, Mr Skandarajah Selvarajah, argued that judicial mercy was justified and that the sentence should be lower than the mandatory minimum of eight years' jail and 12 strokes of the cane for sexual assault by penetration.