N.C. Gen. Stat. § 97-35: How compensation paid for two injuries; employer liable only for subsequent injury.

If any employee receives a permanent injury as specified in G.S. 97-31 after having sustained another permanent injury in the same employment, he shall be entitled to compensation for both injuries, but the total compensation shall be paid by extending the period and not by increasing the amount of weekly compensation, and in no case exceeding 500 weeks.

If an employee has previously incurred permanent partial disability through the loss of a hand, arm, foot, leg, or eye, and by subsequent accident incurs total permanent disability through the loss of another member, the employer's liability is for the subsequent injury only. (1929, c. 120, s. 35.)