What is self-cleaning glass?

Self-cleaning glass is glass with a special 'hydrophilic' and 'photocatalytic' coating on one face. This coating is activated using UV rays present in daylight. The photocatalytic action actually breaks down organic dirt that lands on the surface and prevents inorganic (mineral) dirt from sticking to it. Hydrophilic means that it loves water so when it rains or is hosed down the water sheets across the surface, thus rinsing the broken down dirt away and drying more quickly and uniformly. Windows therefore stay cleaner for longer and are easier to clean if necessary.