Why does photo chromatic glass turn grey in sunlight?

Photo chromatic glass contains extremely small crystals of silver chloride, silver bromide or silver iodide. Silver chloride is especially sensitive to ultraviolet radiation and splits into silver and chlorine. Silver causes the glass do darken. When the source of light is removed, the reaction gets reversed and the glass comes back to its original colour.

Funny Logic

• Because ‘shady’ characters can’t bear the sunlight.