Discussion These results suggest that, when the contact lens is in situ, the application of condenser field short-wave diathermy to the eye in the antero-posterior plane will result in inefficient heating through screening by the corneal and haptic portions of the lens. Secondly, current concentration at the perforation can occur, with subsequent overheating in the region of the ciliary body and possible serious consequences. Thirdly, even with lateral application, which is an inferior technique, some screening would occur in the anterior chamber. A corollary, which was suggested by Sarwar (1956) in this connexion, is that the efficiency of short-wave therapy in orbital cellulitis might be increased by fitting a contact lens, without a perforation, during treatment. This would tend to encourage increased current around the eye with more efficient heating of the peri-ocular tissues, but if this effect is not required it appears desirable to remove contact lenses during the application of shortwave therapy to this area.