A teenager has suffered irreparable sight loss after living on a diet of chips and fries. He first saw his doctor at age 14, complaining of tiredness, but his condition deteriorated and by the age of 17 he had "permanently impaired vision." He was described as a fussy eater since birth and mainly lived off a diet of french fries, Pringles, white bread, processed ham slices and sausages. Here is Dr Denize Atan from Bristol Eye Hospital, who treated the patient.