Self-cleaning tech story not complete

The recent story on self-cleaning glass technology is definitely worthwhile in explaining the difference between hyrophobic (commonly used by aftermarket sprays for windshields) and hydrophilic (used by the major glass makers). However, one very important aspect was left out: the "dirt-destroying" or photocatalytic action.
Some so-called "self-cleaning" glass products are only hydrophilic. There are only two (maybe three) self-cleaning glass products that have two self-cleaning processes: photocatalytic and hydrophilic. The photocatalytic action continuously attacks, loosens and breaks down dirt.
This is an important distinction to make in talking with the industry, homeowners and business owners. Not all "self-cleaning" glass products are created equally.