Polarized sunglasses work by filtering out horizontally polarized light, which significantly reduces glare and improves visual clarity.
Understanding Light Polarization
Light waves travel in all directions. When light reflects off a flat surface like water or a car hood, the reflected light tends to become horizontally polarized, meaning the light waves vibrate predominantly in a horizontal direction. This horizontal light is what we experience as glare.
The Polarized Lens
Polarized sunglass lenses are engineered with a special filter that contains long molecules all aligned in the same direction. This alignment is crucial for how the filter works.
- Vertical Openings: The filter is designed to have what we can think of as vertical openings for light to pass through, as referenced in the provided reference: "the filter creates vertical openings for light."
- Selective Light Transmission: Only light waves that are vibrating vertically (approaching your eyes vertically) can pass through these vertical openings. The lens blocks horizontal light waves.
- Glare Reduction: By blocking the horizontally polarized light, the lenses drastically reduce glare.
Practical Implications
Here's a simple breakdown of the effect:
| Light Type | Polarization | Effect on Vision | Result |
|---|---|---|---|
| Direct Light | Unpolarized | Normal Vision | Passes through mostly unaffected |
| Reflected Light (Glare) | Horizontal | Disrupts/Obscures vision | Blocked by polarized lenses, reducing glare |
Benefits of Using Polarized Sunglasses
- Reduced Glare: Especially effective on water, snow, and shiny surfaces.
- Improved Clarity: Enhanced vision, especially in bright conditions.
- Enhanced Contrast: Makes colors more vivid.
- Reduced Eye Strain: By reducing glare, they decrease the stress on your eyes.
Examples
- Fishing: Polarized sunglasses allow anglers to see below the surface of the water by reducing glare.
- Driving: They reduce the glare from car hoods, roads, and other vehicles.
- Water Sports: Essential for visibility and comfort when on the water.
In summary, polarized sunglasses reduce glare by allowing only vertically oriented light waves to pass through, as the filter in the lens creates vertical openings for the light. This blocks horizontal light waves, which are responsible for glare, improving visual clarity and reducing eye strain.
