Polarised sunglasses are special eyewear with lenses designed to improve vision in strong sunlight. They protect the eyes from glare, a phenomenon that occurs when light bounces of objects in a way that obstructs vision. However, polarised glasses are not appropriate for every occasion. They have disadvantages that make them impractical in certain situations.
Not Appropriate for Snow Sports
In some specific conditions, polarised sunglasses can be inefficient for use during snow sports. Polarised sunglasses can make it difficult to differentiate ice patches as a result of sunbeams reflecting off the snow during downhill skiing or snowboarding. This can be very dangerous, because if the skier or snowboarder doesn't see where he is heading, he has no time to react and can fall.
Not Always Appropriate for Driving
Although the main feature of polarised sunglasses is the ability to reflect glare, which makes them excellent for driving, they can in some circumstances be unsuitable driving. Polarised glasses make liquid crystal displays (LCDs), which also reflect polarised light, practically impossible to read from some angles. These type of displays are very commonly found in dashboards of cars and other motorised vehicles, which means that wearing them during driving can potentially be dangerous.
Not Appropriate for Flying
Polarised sunglasses can also be dangerous for pilots. Although polarised sunglasses were first worn by pilots, their applicability in this profession has faltered with the widespread of LCD screens in dashboards of aeroplanes. As pilots cannot afford to lose sight of the dashboard, polarised glasses are not appropriate eyewear for them.
Polarised sunglasses tend to be more expensive than ordinary sunglasses. If you are looking for sunglasses for winter sports, driving or flying, polarised lenses may not be worth the extra expense.