A light guide module for a holder 35 that is fittable to a portable electronic device 33 having a camera 45 and a flash 43, such as a camera phone or mobile phone, comprises a solid light guide 65, rather than a bundle of optic fibres, having a chamber within which a cowl 59 extending from a lens holder 55 and lens 57 are located. In use, the lens holder 55 is arranged to be proximate the camera of the device and the light guide 65 has an extending leg portion 67 which may be aligned with varying positions of flashes on different devices and is configured to reflect fight emitted by the flash so that the light extends generally in a direction parallel with the cowl 59 via a tip 39 to illuminate a subject. The arrangement may be used as an otoscope or ophthalmoscope.
