Clutterblindness

Clutter Blindness
"Clutter blindness is defined as a person's literal inability to see his clutter in front of him. The person may perceive that there is a pile of newspapers, dishes, or other items collecting in an area, but her mind minimizes or just flat-out ignores the mess. In extreme hoarders (levels 4 and up), ths mental "blindness" is progressive until the issue is brought to light, and then they're overwhelmed by the mess and unable to do anything about it."

From: On Clutter Blindness: What It Is, and Some Ideas on How to Fight it.