How can we reconcile the Hadith of the blind man whom the Prophet permitted to pray in his house, with the Hadith of the other blind man for whom the Prophet prayed in a spot in his house to be taken as a place of prayer?

There is no contradiction between the hadiths reported concerning congregational prayer for the blind. If a blind person cannot find a guide, he is excused from attending congregational prayer, as was the case with Itban ibn Malik. As for the hadith of Ibn Umm Maktum, it is interpreted to mean that he sought permission to be excused from congregational prayer while still obtaining its virtue. The Prophet, peace and blessings be upon him, then informed him that he found no such dispensation for him. The meaning is not that it is obligatory for the blind person. Rather, the command to answer the call is a recommendation and an explanation of what is better and greater in reward. This is supported by the hadith, "Whoever hears the call [to prayer] and does not come, there is no prayer for him except for one with an excuse." Among the excuses is blindness, if one cannot find a guide.