Comment Re:when dirty? (Score 4, Insightful) 194
The data density in bluray means that the pits are far, far, far, far too small for dirt to get stuck in, or on. Think of it like placing a pebble on a beach. There are pits between sand grains but the size disparity means it acts like a flat surface for most intents and purposes.
Not only this, but presumably the pits can be under the glass, just as they are under polycarbonate on a disc. Then the pits are not exposed to dir, and a normal washing will remove surface dust, bird poop, etc.