Question

Why do polarized sunglasses block out some reflected light (glare) but do not block out light that has not been reflected?
(A) Some reflected light is at least partially polarized
(B) Some reflected light changes frequency
(C) Some reflected light is red-shifted
(D) Some reflected light is at least partially diffraction
(E) Some reflected light splits into multiple photons

Answer 1

Hint Polarized sunglasses allow only one component of light in a particular direction to pass through it. The surface light is incident on tends to reflect only light vibrating in a particular plane. Direct natural light vibrates in all directions.

Complete step by step answer
Generally, natural light, such as light from the sun or a bulb, propagates in a particular direction but vibrates in all possible directions. When incident light from these sources strikes the surface of a body the vertically vibrating components tend to get transmitted into the surface and tend to reflect the horizontally vibrating components. Hence, the reflected ray tends to become polarized, thus are always at least partially polarized.
Polarization is the property of light (actually all transverse waves) in which all light can be filtered to allow vibrations in one plane cutting out all other planes of vibration. This filtration is done by materials called Polaroid. Polaroid is slit in one direction to filter out rays in other directions.
However, as described above, reflected light tends to vibrate in the horizontal direction hence partially polarized. At some specific angles depending on the surface of reflection, it becomes completely polarized.
Polarized sunglasses are special glasses that contain laminated filters usually designed to allow only vertically vibrating light to pass through. Thus, we can see that horizontally vibrating light which is reflected from surfaces is cut off by the sunglasses. But since direct light vibrates in all directions, the glasses cannot cut off the light in the vertical direction.
Hence, the reason why polarized sunglasses block reflected light is because they are at least partially polarised.
The correct option is A.

Note
In real life, even though undesired in vision as it creates glare, reflected polarized light is still used in practice, as it is less expensive and can be easily made. Polarized lights in general have numerous applications, such as in microscopy and imaging.