What does a polariscope check?

A polariscope is an instrument commonly used to assess the optical properties of materials, particularly focusing on evaluating the stress and strain within clear plastics and glasses. The primary function of a polariscope in this context is to determine whether a lens material is suitable for use by checking its impact resistance and ensuring it can withstand sudden forces without breaking or deforming.

When light passes through a polariscope and interacts with the material being tested, any internal stresses will cause the light to become polarized. By analyzing the patterns and colors produced, an optician can infer the presence of harmful stresses that might compromise the material's integrity in practical applications, particularly in eyewear.

The other options—color accuracy, optical clarity, and surface tension—are not the main focus of a polariscope's function. Color accuracy pertains more to the visual perception and calibration of light wavelengths, optical clarity relates to the absence of visual obstructions in the lens, and surface tension is more of a property associated with liquids rather than solid materials used in optics. Consequently, the polariscope is specifically tailored to evaluate impact resistance primarily through its examination of internal stresses.