A retrofit-style lamp is disclosed. The retrofit-style lamp includes a plurality of light sources, and a one-dimensional linear batwing lens. The one-dimensional linear batwing lens beam shapes light emitted by at least two light sources of the plurality of light sources. The retrofit-style lamp also includes a housing including the plurality of light sources, and attached to the one-dimensional linear batwing lens. The combination of housing and lens is then itself fitted with endcaps, including electrical connectors, for placement within a fixture, such as within an existing conventional fluorescent tube fixture located within a storage structure, for example a refrigeration case. Alternatively, the plurality of light sources, the one-dimensional linear batwing lens, and the housing may be formed, along with a power supply, as a standalone retrofit fixture for use in enclosed storage structures, such as refrigeration cases, where the retrofit fixture replaces a conventional fluorescent fixture.