Lighting fixture lens retainer

In a preferred embodiment, a lighting fixture lens retainer for a lighting fixture of the type having a generally horizontally extending first lens held in upper and lower fixture members by insertion of first and second mounting flanges formed, respectively, along upper and lower edges of the first lens inserted into first and second mounting grooves formed, respectively, along the upper and lower fixture members, the lighting fixture lens retainer comprising: a retaining member being disposed within the lighting fixture and being movable between a first, open position in which the retaining member is spaced apart from an inner surface of the first lens and a second, securing position in which the retaining member bears against the inner surface of the lens in such manner as to secure the first mounting flange in the first mounting groove.