Abstract: A security device for a means of transport comprising a radiation source to direct radiation into the eye of a person intending to take control of the means of transport, so that the radiation is internally reflected within the eye and emerges from the eye with a substantial spectral content corresponding to the spectral content of food flowing through the retina of the eye, and a receiver arrangement to receive the radiation emanating from the eye of the person and to perform a spectral analysis of the reflected radiation to determine the concentration of at least one chemical within the blood of the person, the device further comprising an alarm unit to generate an alarm and/or an immobilizer unit to immobilize the means of transport, the or each unit being responsive to the said determination of concentration when the concentration of the said chemical is outside a permitted threshold range.

Abstract: A security device for a means of transport comprising a radiation source to direct radiation into the eye of a person intending to take control of the means of transport, so that the radiation is internally reflected within the eye and emerges from the eye with a substantial spectral content corresponding to the spectral content of food flowing through the retina of the eye, and a receiver arrangement to receive the radiation emanating from the eye of the person and to perform a spectral analysis of the reflected radiation to determine the concentration of at least one chemical within the blood of the person, the device further comprising an alarm unit to generate an alarm and/or an immobiliser unit to immobilise the means of transport, the or each unit being responsive to the said determination of concentration when the concentration of the said chemical is outside a permitted threshold range.

Abstract: The device comprises a scleral contact lens (1) for locating and supporting the device on the eye and has an optical system with at least one discrete light source, e.g. an optical fiber (9) or a light emitting diode, and at least one discrete light receiver, e.g. an optical fiber (10) or a photodetector, mounted within a carrier (6) on the scleral contact lens (1). The device may be used for spectrophotometric analysis of the retina (31) enabling it to be used in a wide variety of diagnostic and monitoring techniques. In a further arrangement (FIGS. 5 and 6) the device may be used to provide infra-red pupillometry. Further sensing devices may also be provided on the contact lens (1).