My definition of a human right is human rights are inalienable, and they do not require someone else to provide it. The purpose of government is to protect those rights. (As written in the Declaration of Independence.)

The point of jail is to protect society from people who violate other peoples' rights. Jail shouldn't be about punishment, torture, etc.

It's well known that removing stimulation from people causes them to go insane. Hence, such is tantamount from torture. While that isn't specifically about book reading, preventing a person from reading, human contact, etc., is removing stimulation. Removing all stimulation violates human rights.