blind spot 
noun
1 Anatomy The point of entry of the optic nerve on the retina, insensitive to light.Intriguingly, within the part of the cortical map that represents the region of visual field that can be seen by only one eye, nerve cells receive input from the region of retina immediately surrounding the blind spot....
- This hole in the retina creates a blind spot in the eye, a flaw that again would be avoidable with a priori design.
- Our retinal blind spots rarely cause any difficulty, but rarely is not the same as never.
2An area where a person’s view is obstructed: the rear-view mirror eliminates blind spots on both sides of the car...
- In 1997 Transport Canada introduced a regulation for school buses to have a more complex mirror system fitted to extend the driver's view of blind spots.
- Radar systems, sensors or cameras on both sides of a vehicle (they are here already: I drove a Toyota Corolla Verso a couple of weeks ago with them) can eliminate blind spots.
- Trucks were also fitted with CCTV cameras, which allowed the driver to see the back of the vehicle and eliminated any blind spots.
2.1An area in which a person lacks understanding or impartiality: Ed had a blind spot where these ethical issues were concerned...
- This blind spot, this stunning lack of historical perspective, robs much of the American Left of intellectual credibility.
- While on the topic of the blind spot represented by African issues in New World news media (American and Trinidadian both), my roommate Lauren has a great post on the problem.
- Coaches can give crash courses to inexperienced executives or impart new skills to accomplished managers with blind spots in some areas, like a slowness in making decisions or a clumsy speaking style.
3 Telecommunications A point within the normal range of a transmitter where there is unusually weak reception.He finally told his phone company to deactivate his roaming service - but not everyone does that, because it means they are then unable to make or receive phone calls in coverage blind spots....
- With blanket coverage, users can easily move within the zone without losing their network connection, in-building blind spots excepted, of course.
- Its claims to ‘panoptic’ range notwithstanding, it has its blind spots.