The correct answer is option 2 - polaroids.

Polaroids are special types of lenses that are used in 3-Dimensional (3D) glasses. These glasses are designed to create the illusion of depth in 3D films or movies. The polaroid lenses in the glasses have a specific orientation that allows them to block certain light waves while allowing others to pass through.

When you wear 3D glasses while watching a 3D film, each lens in the glasses has a different polarizing filter. This means that each lens only allows light waves of a specific orientation to pass through. The result is that each eye sees a slightly different image, which creates the perception of depth or a 3D effect.

So, in summary, spectacles used for viewing 3D films have polaroid lenses because they are specifically designed to separate different images and create the illusion of depth.