Andreas Stang, one of the study's authors from the Essen University Clinic, said 118 patients with a type of eye cancer called uveal melanoma had used cellular phones and other equipment deploying radio waves more often than 475 healthy patients.

Scientists have disagreed whether there is a link between cancer and cell phone usage. Studies, many funded by the wireless industry, have given conflicting results. The concern over mobile phones stems from the fact that when used, they emit low levels of radio frequency energy or radiation which at high levels can cause biological damage, according to the U.S. Food and Drug Administration (news - web sites). The effects of low levels of such radiation, however, is still a matter of research.

Michael Foerster of Berlin's Free University expressed doubts about the results of the University of Essen study.

``The problem with the study is that it did not measure how much radiation the studied people had,'' he said. ``Without such a detailed energetic study, such results are biostatistical garbage.''

Uveal melanoma is quite rare and only impacts a few people in 100,000, and the public should not be especially worried about it, Stang said.