(Matt McClain/For The Washington Post)

In a move to improve visibility in subway stations long known for annoying pockets of dimness, Metro says it will spend $5.5 million to install better mezzanine lighting throughout the underground rail system, part of a larger plan to brighten other parts of stations in the future.

Responding to years of complaints — especially from visually-impaired riders — the transit agency recently finished upgrading the mezzanine lighting in the Bethesda, Gallery Place, Judiciary Square, Metro Center and Smithsonian stations and expects to be done installing new lighting in the L’Enfant Plaza station this month. On Thursday, Metro announced that it plans to brighten the mezzanine lighting in the system’s 41 other underground stations by 2015.

“The new lighting will provide better visibility and, in turn, improve safety, security and the overall customer experience for riders,” General Manager Richard Sarles said in a statement. As for the $5.5 million cost, Metro spokesman Dan Stessel said the agency plans to eventually spend “several times this amount” to brighten additional station lighting.

“We are extremely pleased that Metro is listening to the concerns of the low-vision community,” said Barbara Milleville, president of National Capital Citizens With Low Vision. As a result of the new lighting at Judiciary Square, she said, several riders who are visually impaired have reported that they are better able to navigate the mezzanine.

Milleville, who has limited vision, worked with members of Metro’s Accessibility Advisory Committee to audit stations last year. The group found poor lighting in many areas of the underground system.