Ulster's Stephen Ferris has a finger poked into his eye against Stade Francais
Stade Francais pair Julien Dupuy and David Attoub have been cited following alleged gouging incidents in the Heineken Cup defeat by Ulster.
Ireland flanker Stephen Ferris felt he was the victim of the incidents late on in a game which Ulster won 23-13.
Citing commissioner Tony Lamaway charged both with making contact with the eye/eye area of Ferris.
Punishments for the offence range from a 12-week ban at the lower end of the scale to a maximum of three years.
Dupuy is the current first choice scrum-half for France, and - if found guilty - a ban would be likely to keep the former Leicester player out of next year's Six Nations tournament.
The 25-year-old has six caps, playing in the two-Test series against New Zealand in the summer and games against Australia, Samoa, South Africa and the All Blacks in the November Tests.
"I was at the bottom of a ruck and felt my eyes being tugged at," said Ferris.
"I was furious. There was argy-bargy throughout the game, and I don't mind that, rugby is a physical game.
"I would hate to get anyone cited and if someone hit me a dig in the jaw I would take it and get on with the game, but not when someone goes for your eyes."
An official ERC statement said that an independent judicial officer will be appointed as soon as practicable.
Ulster and Stade Francais are both level on nine points at the top of Pool Four with the return fixture in Brussels next Saturday.