What instrument uses polarized light to display strain patterns in materials?

The instrument that utilizes polarized light to display strain patterns in materials is indeed the Colmascope. This device is specifically designed to evaluate stress and strain in transparent materials by showcasing how polarized light interacts with the material under examination. When light passes through a material that is under stress, it can alter the light's polarization, allowing the Colmascope to reveal intricate patterns. These patterns, known as isochromatic or isoclinic fringes, are crucial for analyzing the internal state of stress in the material.

In contrast, the other options serve different purposes. A Vernier Caliper is primarily a precise measuring tool used to measure the dimensions of an object, such as length, width, and depth, not for analyzing strain. A Pressure Analyzer is utilized for measuring the pressure within a system or material, but it does not focus on stress analysis through light patterns. Lastly, a Lensometer is designed specifically for measuring the optical properties of lenses, such as prescription strength, but it does not involve the use of polarized light to assess material strain.