Quick Answer: Most marine electronics use polarized filters that, when viewed through polarized sunglasses at certain angles, cause the screen to appear black or distorted. This "blackout" effect happens because the two polarized filters are perpendicular to each other, blocking all light from reaching your eyes.
If you spend time on the water, you know that polarized sunglasses are essential. They cut through the blinding glare of the ocean, allowing you to see submerged obstacles and marine life with clarity. However, many boaters encounter a frustrating problem: their expensive chartplotters, fishfinders, and digital gauges seem to "disappear" or turn completely black when they put their shades on.
The Science of the "Blackout" Effect
The issue isn't a defect in your sunglasses or your electronics; it's a matter of physics. Most liquid crystal displays (LCDs) used in marine environments are themselves polarized. They use a thin film to control the light that forms the images on the screen.
Polarized sunglasses work by blocking horizontal light waves (glare). When the polarization of your screen aligns perfectly with the polarization of your lenses, the light passes through. But if you tilt your head or if the screen is mounted at a 90-degree angle to your lenses, the two filters work together to block 100% of the light. This is why a screen might look fine from one angle but go dark as soon as you move.
Why 2nu TrueView Optics™ Make a Difference
At 2nu, we understand that professional boaters and anglers can't afford to lose sight of their navigation data. Our TrueView Optics™ are engineered to provide maximum glare protection while minimizing the interference with digital displays.
Unlike standard polarized lenses that can cause severe distortion or complete blackouts, our advanced lens technology is optimized for high-contrast environments. By choosing the right lens tint—such as our amber or copper options—you can significantly improve your ability to read screens even in bright, direct sunlight.
Tips for Better Screen Visibility on the Water
- Check Your Mounting Angle: Sometimes, simply rotating your display by a few degrees can eliminate the blackout effect.
- Adjust Screen Brightness: Increasing the backlight on your marine electronics can help "push" more light through the polarized filters.
- Choose the Right Lens Tint: Amber lenses are particularly effective for enhancing contrast and reducing the strain of reading digital displays in variable light conditions.
- Invest in Quality Gear: High-performance watersport sunglasses are designed specifically for these challenges, offering a balance between glare reduction and digital clarity.
Protecting Your Investment
Saltwater and constant sun exposure are brutal on both your eyes and your gear. To ensure your sunglasses continue to provide peak performance, it's crucial to understand how to care for them. Proper maintenance prevents the specialized coatings from peeling and ensures that your vision remains sharp, whether you're looking at the horizon or your fishfinder.
By understanding the relationship between polarization and digital displays, you can choose the right equipment to stay safe and informed on every voyage.