The human eye is incredibly sensitive towards ionizing radiation, and thus, should be protected with, for example, X-ray protective glasses. Particularly important is the correct fit of the glasses: The X-ray protective glasses must fit particularly tight to the cheeks and the sides of the user’s face. The reason for this is that the secondary radiation emitted from a lying patient does not only hit the front of the eye lenses but rather comes from below or from the sides at different angles.