Rabeni's suspension runs until July 7 and he will miss Leicester's bid for an Anglo-Welsh Cup and Premiership double.
The Rugby Football Union disciplinary committee decided on 14 weeks to ensure Rabeni was not available for the rest of this season or any potential summer internationals for Fiji or the Pacific Islands.
Lawrence Dallaglio was also handed a back-dated one-week ban for striking Leicester prop Julian White during Wasps' Anglo-Welsh Cup semi-final defeat on March 22.
Dallaglio had already been suspended by his club for their league win at Leicester last weekend and will be free to play for Wasps in their next game, against Worcester on April 12.
Harlequins centre De Wet Barry was found not guilty of a deliberate late charge on Newcastle's Mathew Tait.
The England centre required lengthy treatment on the field, and Barry was sent off following the incident - but the panel, chaired by His Honour Judge Jeff Blackett, cleared the South African.
Rabeni's case was up last at the disciplinary session at the Bloomsbury Holiday Inn in London on Monday evening.
The maximum suspension for gouging is two years, and Rabeni's ban comes in on the lower end of the scale - with the minimum entry point on the RFU table set at three months.
Nevertheless, it still rates as one of the heftiest suspensions dished out in the history of the Premiership and shows the authorities have no leniency for eye-gouging.
Last season, Northampton hooker Dylan Hartley received a 26-week ban for two cases of eye-gouging and missed out on an England tour and potential World Cup place because of it.
In 1998, England prop Kevin Yates received a six-month ban for biting an opponent - while in 2006 the versatile Tongan international Epi Taione was suspended for 18 weeks for the same offence.
Rabeni had been in destructive form in recent weeks, and Leicester will miss his presence against physical Ospreys duo Gavin Henson and Sonny Parker in the Anglo-Welsh Cup Final at Twickenham on April 12.
He would also have been a key player in the Tigers' Premiership challenge, which was checked last weekend by a home defeat to Wasps.