Imprisoned for more than 43 years in the United States, Mumia Abu Jamal suffers from irreversible vision loss that can lead to permanent blindness. His eyesight is threatened by two correctable conditions. The Pennsylvania Department of Corrections and his contracted health care provider, Wellpath, allowed his eyesight to deteriorate to the point of rendering him functionally blind. In particular, his treatments for his cataract and recently diagnosed diabetic retinopathy were delayed for several months. His supporters encourage people to contact the prison to demand that he receive appropriate treatment (see here).
Source: https://secoursrouge.org/usa-mumia-abu-jamal-victime-dune-politique-de-negligence-medicale/