Why is heat stability important in a polarized lens?

Heat – such as in a car on a warm day – can alter polarized lens colours. Also, if left in a car for extended periods of time in extreme heat the polarizing film may be damaged.

However, this is not the case with NuPolar polarized lenses which are the most heat and colour stable lenses available. This means NuPolar lens colours remain true and rich, and do not fade over time – even when left in a hot car.

Heat stability of polarized lenses is also extraordinarily important during laboratory processing. Polarized lenses can often be subjected to high levels of heat (120 – 140°C), particularly during hard coating and anti-reflective coating. As a result, lens colour can change due to thermal degradation.

NuPolar’s proprietary HT Film Technology ensures NuPolar lenses offer more colour stability than any other lens on the market – even during laboratory processing – so that colours remain rich and true.

Often polarized lenses will have an anti-reflective coating on them. Extreme heat can also impact the anti-reflective coating. Responding to the extreme heat, the lenses and the anti-reflective coating can expand at different rates. This can result in crazing – a web of fine cracks on the lens.