Provided is a novel therapeutic agent for glaucoma, which has sGC-activating action. A therapeutic agent for glaucoma or an ocular hypotensive agent, which contains, as an effective component, a compound represented by Formula (I-a) or Formula (I-b) and having a Log D value of more than 1.5 and less than 2.5, or a pharmaceutically acceptable salt thereof. [In formulae (I-a) and (I-b), each symbol is as defined in the description.]