What was found
CLT - FLT 1414, EN ROUTE STX TO CLT. WHILE IN CRUISE FLIGHT, THE CAPTAIN'S WINDSHIELD ARCED, AND THEN CRACKED. CREW DECLARED AN EMERGENCY AND DESCENDED TO FL 200 TO REDUCE PRESSURE. FLIGHT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED THE CAPTAIN'S WINDSHIELD. OPERATIONALLY CHECKS OK.