(a) Upon an original registration issued on or after April 1, 1981, or upon the renewal of a registration, the original of which was issued prior to April 1, 1981, proof of severe disability will be required and may be required upon subsequent renewals. Such proof shall consist of a letter signed by a physician, physician assistant, nurse practitioner, optometrist, or podiatrist on his or her letterhead (if licensed outside of this State, must include state of licensure and license or certification number), or of a statement from the Commissioner for the Blind and Visually Handicapped, or a certification from the Office of Vocational Rehabilitation, or from a hospital, clinic or medical facility. A copy of the letter or statement is acceptable as is a copy of a physician's, physician assistant’s, nurse practitioner’s, optometrist’s, or podiatrist’s letter submitted to obtain a New York State Handicapped Parking Permit or a New York City Special Vehicle Identification Permit. The letter or statement shall have been issued within the preceding year, except at the discretion of the district director or county clerk. The letter, certification or statement must certify that the applicant has one or more of the permanent disabilities or conditions listed in section 24.2 of this Part.

1. (1) Certification of disability by a podiatrist. A podiatrist duly licensed to practice podiatry in this State may certify only those conditions which he or she treats in the course of the practice of podiatry, as defined by section 7001 of the Education Law.
2. (2) Certification of disability by an optometrist. An optometrist duly licensed to practice optometry in this State may certify only those conditions which he or she treats in the course of the practice of optometry, as defined in section 7001 of the Education Law.