Litracon is a light-transmitting concrete invented by architect Aron Losonczy in 2001. It is produced by casting thousands of optical fibers directly into concrete mixtures. When light enters one end of the embedded fibers, it is transmitted through the concrete by total internal reflection in the fibers. Litracon has advantages like reduced lighting costs and illuminated structures, though it is more expensive than traditional concrete. Potential applications include translucent walls, ceilings, sidewalks, and other structures.