Ocular surface interferometry devices, systems, and methods are disclosed for imaging an ocular tear film. An imaging device can be focused on the lipid layer of the tear film to capture optical wave interference interactions of specularly reflected light from the tear film combined with a background signal(s) in a first image, wherein the specularly reflected light may be produced from various portions of the ocular tear film by obliquely illuminating various portions of the ocular tear film with a multi-wavelength light source, such as in a tiling pattern(s). The imaging device can also be focused on the lipid layer to capture a second image containing the background signal(s) present in the first image. The second image can be subtracted from the first image to reduce and/or eliminate the background signal(s) in the first image to produce a resulting image, which can used to measure a tear film layer thickness.