A Thames man who beat his partner so hard it caused the pupil of her eye to rupture has been jailed for three years and four months.

Teokotai Oropai Piho, 30, appeared for sentencing in the Hamilton District Court on Tuesday, after earlier pleading guilty to a charge of wounding with intent to cause grievous bodily harm.

Fairfax reports Piho assaulted his partner as she was trying to take a shower on the morning of Wednesday, July 6.

He later told police the woman suffered the eye injury because she accidentally walked into his thumb.

Police's summary of facts reveals on the mornng of the assault, the victim had returned to her's and Piho's Thames home following an argument between the pair the previous night.

She'd just stepped into the shower when Piho entered the room, began yelling at her then started punching her in the head and stomach before throwing her against the walls of the shower and bathroom. He then proceeded to stomp on her stomach.

The entire incident had been witnessed by their four young children, reports Fairfax.

The victim suffered extensive swelling to her forehead and bruising to her stomach, legs, arms and torso, and was also found to have numerous bite marks on her arm. She is also at risk of losing full use of her right eye and has had to undergo specialist hospital treatment.

Piho initially admitted to police he'd pushed his partner with an open hand and punched her once in the ribs. While his explanation for the eye injury was his partner had approached him from behind, he'd put his hand up and she'd walked into his thumb.

From a starting point of four years and nine months, Judge Connell allowed a 16 month discount for Piho's guilty plea, and an additional month for his remorse and other factors, ending with a final sentence of three years and four months.

– stuff.co.nz