Application Note

UV Measurement Of Sunglasses Using A Back-Thinned CCD Spectrometer

Source: Ocean Optics, Inc.

Introduction
In assisting thousands of customers over the years, we’ve discovered that everyone has a slightly different idea of what constitutes ultraviolet light. For some, it’s the light just beyond human vision that some animals can see (300-400 nm). For others, it’s ionizing radiation that propagates only in a vacuum, below 120 nm.  What we can all agree on, however, is that UV light is not good for our eyes, and that a proper pair of sunglasses needs to block these harmful rays. 

Ultraviolet light can be broken into several wavelength ranges. UVA, UVB and UVC can all damage tissue and accelerate aging of the skin. Since most UVC rays are filtered out by the atmosphere, sun protection focuses primarily on UVB rays, which can damage eye structures such as the cornea, lens and retina.  Also, UVA can contribute to tissue damage indirectly by generating reactive species, but is less damaging and not always blocked by protective gear.