Perimeter lighting fixtures produce vertical illuminances that help define indoor spaces. Vertical illumination along the perimeter of a room improves the overall perception of brightness, makes the space feel larger, and helps balance luminance ratios within the visual field. Successful perimeter lighting contributes to a sense of pleasantness and positively influences the impression of building occupants on the environment. Perimeter lighting fixtures include cove lights, wall washers, cornice lights, and valance lights. Cove lights are concealed in perimeter coves and project a pleasant lighting pattern by distributing light over the ceiling and upper wall. Wall washers uniformly distribute light across a wall from top to bottom. Cornice lights are surface mounted light fixtures that are attached to the ceiling, with the light emitting surface shielded by a panel parallel to the wall. Valance lights are similar to cornice lights except for that they’re installed over windows.