Optical Metrology Systems

How to measure optical coatings, UVA UVB and UV index with a spectrometer

Optical filter reflectance and absorbance spectroscopy for eyewear.

Are your glasses really UV protected?

UV light can be really dangerous for the eyes. According to multiple studies, UV rays were linked to eye damage, such as cataracts, macular degeneration, pingueculae, pterygia, and photokeratitis, that can eventually lead to a temporary loss of vision. UV light can be broken into three wavelength ranges:

  • UVA 315–400 nm
  • UVB 280–315 nm
  • UVC 100–280 nm
  • Extreme UV 10 – 120 nm

Most of the sunglasses claim to have UV 400, in other words, 100% protection against UV light. Some eyeglasses have multiple coatings that ensure UV protection. Unfortunately, it’s not always true. Spectrophotometers can analyze the light absorption in lens coatings and provide important information for manufacturers of eyewear. The measurements have to precise to comply with the standards of FDA.


Andrej Mosat

My research interests include applied spectroscopy, photonics, mathematical modeling and rapid development and manufacturing techniques.