Very useful link here Inside Times the only free newspaper for prisoners and their relatives.
http://www.insidetime.org/
There are lists of prison law specialists and many links to help for families of prisoners. PLEASE get on to a prison law specialist NOW they will be on the case within an hour. This is an emergency your husbands sight is at stake.
Do not try to do it your self I know from expierienc it will not work , the prison lawyers will know exactly who to contact and how to get results.
If all else fails then contact the Chaplin at Wandsworth , they are VERY helpfull and do far more than arrange church servces, they will know how to get help in this situation.