Canadian director James Cameron shows 3D glasses as he poses in front of a poster before a promotion event for his latest movie Avatar at the World Economic Forum (WEF), in Davos January 28, 2010. Credit: Reuters/Christian Hartmann

The health ministry said Thursday it had confiscated about 7,000 sets of 3D glasses from Italian cinemas and could collect more of them.

Officials said the glasses pose hygiene problems if they are not properly cleaned between screenings, and that the confiscated glasses did not display tags proving they would not cause short-term vision problems to users.

The missing glasses have had little effect on the success of Avatar in Italy, where it remains the top-grossing film in the country.

Anica, the Italian cinema and audiovisual association, declined comment.