A sun visor having an extensible panel which is received within the main visor body. The main panel includes an elongate slot having a plurality of opposed notches spaced therealong, the slot communicating with a cavity in the main panel. The extensible panel includes a detent mechanism including a pair of biased pins slidable in a track. The pins extend through the slot in the main panel and engage the notches in the slot. The pins may be squeezed together to enable the extensible panel to be moved with respect to the main panel.