Section 25.1381 - Instrument lights(a) The instrument lights must- (1) Provide sufficient illumination to make each instrument, switch and other device necessary for safe operation easily readable unless sufficient illumination is available from another source; and(2) Be installed so that- (i) Their direct rays are shielded from the pilot's eyes; and(ii) No objectionable reflections are visible to the pilot.(b) Unless undimmed instrument lights are satisfactory under each expected flight condition, there must be a means to control the intensity of illumination.Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-72, 55 FR 29785, July 20, 1990