Doublet lenses and doublet lens assemblies, and methods of assembling doublet lenses and assemblies, including a first lens having a convex surface and a concave surface, the concave surface comprising a peripheral portion and a central portion, and a second lens having a convex surface and a concave surface, the concave surface comprising a peripheral portion and a central portion. The peripheral portion of the first lens abuts the peripheral portion of the second lens with an airspace between the central portion of the first lens and the central portion of the second lens. The peripheral portions of the first and second lenses are shaped to fit together in a mating relationship which prevents sliding of the first and second lenses relative to each other in a radial direction after the lenses are brought together.