Vt. Stat. Ann. tit. 23, § 1257

If a motorcycle is not equipped with a windshield or screen, the operator of the motorcycle shall wear either eye glasses, goggles, or a protective face shield when operating the vehicle. The glasses, goggles, or face shield shall have colorless lenses when the motorcycle is being operated during the period of 30 minutes after sunset to 30 minutes before sunrise and at any other time when, due to insufficient light or unfavorable atmospheric conditions, persons and vehicles on the highway are not clearly discernible at a distance of 500 feet ahead.