One of the great advantages of a school specifically for the blind and deaf is that it usually provides important tools for the students to learn to live independently in a sighted and hearing world. They learn valuable life skills they might not get at home from doting parents who cater to them, or from indifferent parents who have no time for a special needs child. It happens.
However, at a school for the blind and deaf, children learn a standard academic curriculum, but also receive other training, often of a vocational nature, to help them find employment when they graduate, especially if they are not interested in college.
Schools for the blind and deaf can also assist their students in accessing resources that might help them later, like government assistance, or getting a service dog. They serve a valuable function for these persons with special needs.