What was found
CLT - FLT 200 EN-ROUTE MSP TO CLT, DURING FLIGHT, THE FIRST OFFICER'S WINDSHIELD BEGAN TO ARC, AND THEN CRACK. CREW PULLED THE CIRCUIT BREAKER FOR THE WINDSHIELD ANTI-ICE HEAT AND DESCENDED TO FL 230. FLIGHT CONTINUED TO CLT WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED THE FIRST OFFICER'S WINDSHIELD. OPERATIONALLY CHECKS OK.