An ophthalmic light instrument includes a plug (1) and a light guide (7) for guiding light (10) to a surgical site in the eye. The plug (1) is configured to be magnetically attractable or attractive and can be positioned and connected releasably with respect to a light source in such a way, that coupling of the light (10) into the light instrument takes place at the focal point (14) of the light source (12). An ophthalmic illumination system includes such a light instrument and a socket of the light source. The socket of the light source (4) is configured to be magnetically attractable or attractive and can be positioned and connected releasably with respect to the light source in such a way, that coupling of the light (10) into the light instrument takes place at the focal point (14) of the light source (12).
