a. 1. Seeing with clearness; acutely perceptive, discerning; as, clear-sighted reason. Syn. -- clear-eyed, perceptive, percipient, perspicacious, clear-headed. [ 1913 Webster + WordNet 1.5 ]
2. having sharp clear vision. [ WordNet 1.5 ]
n. Acute discernment. [ 1913 Webster ]