Is it obligatory for brothers to serve their blind and severely mentally disabled brother, and what is the ruling on their not serving him if the parents request it, and what if the parents fall short in serving him and cast the responsibility upon the children?

If the blind brother is wealthy, then his siblings or parents are not obligated to serve him; rather, he should hire someone to serve him with his own money. However, if he is poor, then his wealthy father must hire a servant for him. If the father is poor and the mother is wealthy, then she is obligated to provide a servant for her child. If the mother is of limited means, then the preponderant opinion is that maintenance (including providing a servant) is obligatory upon the wealthy siblings. If the father commands the siblings to serve, then it appears obligatory to obey him, as long as no harm results to them. It is permissible for whoever serves this brother to look at his private parts and touch them when necessary.