A backlight is provided for a direct-view display. The backlight comprises a plurality of discrete light sources (11), such as light emitting diodes, spaced from a diffuser (5). The light sources are arranged as sets cooperating with a mirror structure (101), which surrounds the set to form a region. The regions substantially tessellate the area of the backlight. Each mirror structure (101) comprises a plurality of mirror segments which are curved and concave in cross-section perpendicular to the diffuser (5). The mirror segments extend from around the light sources (11) towards the diffuser (5). The edges of adjacent mirror segments of adjacent regions meet at a meeting line such that all of the meeting lines are at the diffuser (5) or between the diffuser (5) and the light sources (11).