UVC effects on lenses

[OcularSin]

Does anyone know if there are any negative effects of using UVC (254nm) light on lens materials or treatments i.e. Transitions AR?

[Lelarep]

Unless journal articles have been published, then no. Here on the surface on Earth we never see any significant natural UV-C. Any exposure is strictly artificial. There are multiple wavelengths of UV-C that are used for industrial and commercial purposes, mostly in a germicidal capacity. The most common wavelengths are 230 nm, & between 255 and 280 nm. A new entrant recently is 220 nm, and it is posed to take the UV-C market by storm because they are claiming it is completely human safe due to the nature of its absorption by the outer epithelial layer, which prevents DNA damage. However some are skeptical it is as amazing as it seems.

Generally, you'd need to look up journal articles on the effect of the "Middle Ultraviolet" (200-300 nm)/UV-C. for each material type and lens treatment to know anything about how they respond to it.