Second Sight (1999)

DCI Ross Tanner and his deputy Catherine Tully are investigating the brutal murder of a 19-year-old boy. Among the suspects are a gardener who may have been supplying the boy with drugs, a live-in nanny who may have been having an affair with the boy, an overprotective mother whose new two-year old daughter may have put on strain on the mother-son relationship, a step-father whose work interfered with any intimacy with the boy, and an identical twin of the lastly named 'suspect.' Tanner's skills are tested to the maximum because he is experiencing loss of vision and is hiding the fact until the case is resolved.