(a) If an individual licensed to operate a vending facility on state property requires an assistant, a qualified person with a disability of a visual nature must be given preference for employment. If the commission determines that a person with a disability of a visual nature could not perform the labor for which an assistant is required, or if a person with a disability of a visual nature is not available, a person with a disability that is not of a visual nature must be given preference for employment.
(b) An assistant employed by a blind person licensed by the commission must be approved by the commission, and the deliberate refusal of a blind licensee to comply with this section constitutes grounds for the revocation of the person's license.