The principle behind the use of polarizers in sunglasses is polarization of light to reduce glare.
Here’s how it works:
- Glare is caused by sunlight reflecting off flat, shiny surfaces like water, roads, or car hoods. This reflected light becomes partially polarized, meaning its waves vibrate mostly in one direction (usually horizontally).
- A polarizing filter in sunglasses is designed to block light polarized in the horizontal direction. It contains long-chain molecules aligned in a way that only allows light vibrating in a specific direction (usually vertical) to pass through.
- By filtering out horizontally polarized light, the sunglasses significantly reduce glare, improving visual comfort and clarity.