What is a unique feature of polarized sunglasses regarding glare?

Polarized sunglasses are specifically designed to reduce glare from reflective surfaces, which is one of their primary benefits. The unique feature of polarized lenses lies in their ability to filter out certain types of light waves. When light reflects off horizontal surfaces, such as water, roads, or car hoods, it can create intense glare that makes it difficult to see clearly. Polarized lenses contain a special chemical film that blocks this horizontally polarized light while allowing vertical light to pass through. This significantly reduces the perception of glare and enhances visual comfort and clarity.

While some sunglasses may change tint based on light conditions, which relates to option A, polarized lenses do not alter their tint in such a manner. Additionally, while polarized sunglasses are effective at reducing glare, they do not eliminate all forms of glare, which aligns with option B. Lastly, their effectiveness is not limited to high altitudes, as suggested by option D; polarized glasses work at any elevation where reflective surfaces are present. Therefore, reducing glare from reflective surfaces is indeed the primary and unique feature of polarized sunglasses.