CFR /  Title 14  /  Part 29  /  Sec. 29.1381 Instrument lights.

The instrument lights must--

(a) Make each instrument, switch, and other device for which they are provided easily readable; and

(b) Be installed so that--

(1) Their direct rays are shielded from the pilot's eyes; and

(2) No objectionable reflections are visible to the pilot.