The system using reflection of light from the cornea has the latter reflected light together with an image of the field of view fed to a TV camera (5). The latter has a spectral sensitivity which exhibits a greater amplitude for the reflected light than that from the field of view. The camera video signal (6) is electronically evaluated directly or after intermediate storage to provide analogue or digital voltages representing X and Y coordinates of the point of max. amplitude. A lamp (1) is used to provide a beam directed onto the cornea with the reflected light directed onto the TV camera (5) via special spectacles (3) together with the scene of the field of view via an optical fibre link (4). The scene light may be filtered to ensure that the max. amplitude occurs for the light reflected from the cornea.
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