Mich. Comp. Laws § 257.708a
A motor vehicle shall not be operated on the public highways of this state unless it is equipped with a windshield of sufficient dimensions to protect the driver and occupants from insects, other airborne objects, and highway surface water and debris, when the motor vehicle is moving forward. A farm tractor, other implement of husbandry, and historic vehicles as defined in section 803a are exempt from this section. When a motorcycle operated on the public highways of this state in excess of 35 miles per hour is not equipped with a windshield, the operator shall wear goggles with transparent lenses or a transparent face shield or eyeglasses, which goggles, eyeglasses, or face shield shall be of shatter resistant material and of sufficient size to protect his eyes against insects, other airborne material, and highway surface water and debris.
MCL 257.708a