S.C. Code Ann. § 56-1-270: Suspension, revocation, or restriction of license on re-examination.

The Department of Motor Vehicles having good cause to believe that a person holding a South Carolina driver's license is incompetent or otherwise not qualified to be licensed because of physical or mental disability may, upon written notice of at least ten days to the licensee, require him to submit to an examination. Upon the conclusion of such examination the department shall take action as may be appropriate and may suspend or revoke the license of such person or permit him to retain such license or may issue a license subject to restrictions permitted under Section 56-1-170. The license of any person may be suspended or revoked if they refuse or neglect to submit to such an examination.