Sigma has announced, what it calls the world’s first highly shock resistant and scratch resistant clear glass ceramic filter.
It says that the WR Ceramic Filter has roughly ten times the strength of a conventional filter and three times stronger than a chemically hardened glass filter.
Use of this filter will result in extremely high light transmission. The Water-repellent coating applied to the filter results in only 0.24% light from the visible spectrum getting reflected. This ensures minimum flaring and ghosting.
The WR Ceramic filters come in the size 67-105 mm. So all users of DSLR lenses as well as some cine lenses should be able to take benefit of these filters.
Sigma is yet to announce the pricing or availability of these filters.
I normally don't use any filters except polarisers. However, I would be very interested to check these filters because of the quality of light reflectance as well as strength.
Sigma's video of the filter is shared here: https://www.youtube.com/watch?v=_g3J-YpwzHw