49 CFR § 391.64 - Grandfathering for certain drivers participating in vision and diabetes waiver study programs.
(b) The provisions of § 391.41(b)(10) do not apply to a driver who was a participant in good standing on March 31, 1996, in a waiver study program concerning the operation of commercial motor vehicles by drivers with visual impairment in one eye; provided:
(1) The driver is physically examined every year, including an examination by an ophthalmologist or optometrist attesting to the fact that the driver:
(i) Is otherwise qualified under § 391.41; and
(ii) Continues to measure at least 20/40 (Snellen) in the better eye.
(3) The driver provides a copy of the annual medical certification to the employer for retention in the driver's qualification file and retains a copy of the certification on his/her person while driving for presentation to a duly authorized federal, state or local enforcement official.