There are now two main entry qualifications in to the profession of Habilitation Specialists.
If you are coming from outside the field you may like to consider
Habilitation and Disabilities of Sight Graduate Diploma Course at ULC Institute of Education (IOE). https://www.ucl.ac.uk/ioe/courses/graduate-taught/habilitation-disabilities-sight-children-young-people-graddip-specialist-qualification
Successful completion of this course enables you to meet the National Habilitation Standards and Qualify as an Habilitation Specialist on completion of your probationary year. You must still apply for registration and ensure you have achieved the relevant braille levels.
An alternative route for those already qualified as Rehabilitation Workers is the BCU BSC top up course.
Habilitation Work- working with Children and Young People- Top up degree BSC hons http://www.bcu.ac.uk/courses/habilitation-work-visual-impairment-top-up