Kiddush Levana

The mitzvah of kiddush levana has its roots in in the mitzvah of the kiddush hachodesh as explained by Rav Asher Weiss in 'מצוות קידוש לבנה.'

The Magen Avraham (426) says a blind person does kiddsuh levana. Rabbi Akiva Eger says the Maharikash holds only one who actually sees the moon is obligated. This machlokes may hinge on the nature of the beracha, if it is a birchas hanehenin then the Maharikash is right that only one who actually sees the moon and benefits from it can say the beracha. On the other hand, if it is a birchas hashevach, then even a blind person is eligible to say the beracha. 

The Mechabar and Rema (426:4) hold that one can say kiddush levana only after a few days of the month have passed in order to ensure one can at least benefit from the new moon. The Rambam however, holds one can say the beracha immediately (Berachot 10:17.) The Aruch Hashulchan notes this is the opinion of Rashi in Sanhedrin as well. They would seem to hold the beracha is a birchas hashevach. This also fits with the placement of the Rambam where he puts this beracha together with other berachot on natural phenomena.   

The Magen Avraham (426:1) says that woman do not say the beracha because it is a time bound mitzvah. Rav Shlomo Kluger argues it is not a מעשהז"ג for the mitzvah is not limited by time, one is just limited by the facts of life that the new moon only appears sometimes. Rav Moshe Feinstein (Choshen Mishpat volume 2 #47:2) says that the beracha of kiddush levana is not a birchas hashevach or nehinin but is a new takkanah to say a beracha on the new moon as one is able to feel the majesty of Hashem and it is כאילו מקבל פני שכינה. He explains the M.A. means this is a new form of beracha and since it only occurs at specific times, the takkanah is not placed on woman just as they are exempt from time bound mitzvot.