Methods and apparatus for assessing visibility through an optical material

Assessing visibility through an optical material by capturing a digital image of a target through the material, determining its intensity, and using such intensity to determine a visual acuity index for the material. An apparatus for performing the method can assess visibility through an optical material exposed to environmental conditions. The apparatus includes an imaging system with a camera for acquiring digital images of the target through the optical material, a system for exposing the material to environmental conditions, and a system for processing intensities of the target in the acquired digital images. The processing system includes programming for relating the intensity of the target to the visual acuity index, whereby visibility through the optical material is determined.