If you are wondering whether you should get a pair of polarised sunglasses or not for your next long drive in New Zealand, here are some key benefits of polarised lenses that can help on that journey.
Reduces Glare
Polarised sunglasses are particularly useful for long drives in New Zealand because of the diverse landscapes and changing weather conditions that create intense glare. Here’s how they help:
- Glare from wet roads: In New Zealand, where rain showers can be frequent, especially on coastal highways like the Kaikoura Coast, wet roads reflect sunlight. Polarized lenses filter out the horizontal light waves that cause this reflection, reducing the blinding glare and improving visibility, particularly on winding roads.
- Glare from water bodies: Long drives often pass by lakes, rivers, and coastal areas, such as Lake Taupō or State Highway 1 along the Kapiti Coast. The strong reflection of sunlight off water can be dazzling. Polarized lenses cut through this glare, allowing drivers to maintain focus without squinting.
- Mountain and snow glare: If you’re driving on scenic routes like the Crown Range Road between Queenstown and Wanaka, snow-capped mountains and sunny days can create harsh glare. Polarized sunglasses help reduce the intense reflections from snow and distant horizons, ensuring a clearer view of the road ahead.
- Sunset and sunrise glare: In New Zealand, driving at sunset or sunrise can create low-angle light directly in your line of sight, especially on long stretches like State Highway 2 near Hawke’s Bay. Polarized sunglasses reduce this harsh light, making early morning and late afternoon drives safer.
Reduces Eye Strain
Polarized sunglasses help reduce eye strain during long drives in New Zealand by filtering out glare and improving overall visual comfort. Here’s a detailed explanation:
- Glare reduction lowers strain on the eyes: When exposed to intense glare, such as reflections from wet roads or water bodies, your eyes work harder to filter the light. Over time, this leads to eye strain, headaches, and fatigue. Polarized lenses block the horizontal light waves that cause glare, which reduces the strain placed on your eyes. For example, on the State Highway 73 driving through Arthur’s Pass, where the road is often wet or covered in snow, polarized lenses help by cutting through the intense reflections off the road or snowy surfaces.
- Scientific principle of light polarization: Light from the sun is scattered in all directions, but when it reflects off a flat surface like a road or water, it tends to become horizontally polarized. This creates intense glare that strains the eyes as they work to process both the useful vertical light and the distracting horizontal glare. Polarized lenses contain a filter that blocks this horizontal light, allowing only vertically oriented light to pass through. This reduces eye fatigue, especially on long drives such as on State Highway 1 from Auckland to Wellington, where direct sunlight and road reflections can be constant over long stretches.
- Minimizes pupil dilation: Bright light causes your pupils to constrict to reduce the amount of light entering your eyes. However, when glare is involved, your eyes are forced to work harder to adjust between areas of brightness and shadow. This constant adjustment causes eye strain. Polarized sunglasses minimize this effect, helping your eyes maintain a more relaxed state during changes in lighting, such as when driving through varied lighting conditions on the Haast Pass road, where the road can alternate between sunlit valleys and shaded rainforests.
- Long-term comfort on extended drives: Research shows that continuous exposure to glare and bright light leads to cumulative eye strain, which can result in visual fatigue, discomfort, and even a reduction in reaction time. This is particularly relevant on long drives in New Zealand, such as the Milford Road (State Highway 94), where the combination of alpine glare, snow, and reflective surfaces can make the drive exhausting. Polarized sunglasses help maintain visual comfort over long periods by reducing this cumulative strain.
- Prevents squinting: Squinting is a natural response to intense light or glare, but it can cause eye strain, tension headaches, and facial discomfort, especially during extended periods behind the wheel. Polarized sunglasses allow drivers to keep their eyes open without squinting, even when exposed to strong sunlight, such as on State Highway 2 in the Bay of Plenty, where sunny conditions and reflections from the sea can lead to eye strain.
Minimises Reflections
Polarized sunglasses minimize reflections during long drives in New Zealand by filtering out specific light waves that cause distracting glare, which is especially helpful when driving through diverse landscapes. Here’s a detailed breakdown of how this works, supported by scientific facts and specific examples relevant to New Zealand’s roads:
1. Reflection reduction through polarization filters:
Polarized lenses contain a vertical filter that blocks horizontally reflected light, which is the main cause of glare. When light reflects off flat surfaces like roads, lakes, or car dashboards, it often becomes polarized in a horizontal direction. This reflected light creates intense glare, reducing visibility. Polarized sunglasses filter out these light waves, reducing the distracting reflections that impair clear vision.
- For example, driving along State Highway 6 near the Haast Pass, where the road passes through areas with numerous lakes and rivers, the sun reflecting off the water can create intense glare that distracts drivers. Polarized sunglasses help block these reflections, improving clarity and reducing eye strain.
2. Minimizing reflections from wet roads:
In New Zealand, roads can often be wet due to rain, especially in regions like the West Coast or Fiordland, where rainfall is frequent. Wet roads reflect a significant amount of sunlight, which creates distracting reflections that can obscure important road details like lane markings or obstacles.
- On long drives, such as through State Highway 94 (the Milford Sound Road), where rain and wet road conditions are common, polarized sunglasses minimize these reflections, allowing drivers to see the road surface clearly, even when the sun is shining directly onto the wet asphalt.
3. Reducing dashboard and windshield reflections:
Long-distance driving in New Zealand, particularly during sunny days, often causes reflections from the dashboard or windshield to bounce back into the driver’s line of sight. These internal reflections can create visual distractions, especially during sunny midday drives along exposed stretches like State Highway 1 between Christchurch and Dunedin.
- Polarized sunglasses help reduce the impact of these reflections by filtering out the horizontal light waves that reflect off glass and other flat surfaces, allowing drivers to focus better on the road ahead.
4. Scientific basis of glare and reflection:
Scientifically, when light hits a flat surface, like water or asphalt, it gets polarized, meaning the light waves become aligned in a horizontal direction. These horizontally aligned light waves create glare, making it harder for the eyes to process useful visual information. Polarized lenses are coated with a chemical film that absorbs the horizontally polarized light, leaving only the vertically aligned light to pass through, improving visibility by reducing the intensity of reflections.
5. Reflections from snow or ice:
In alpine regions such as Lindis Pass or Crown Range Road, where snow or ice may cover parts of the road during winter, sunlight reflecting off the snow can be particularly blinding. Polarized sunglasses filter out these strong reflections, improving the driver’s ability to see both the road and potential hazards ahead.