Blind–spot

Anatomy. a small area on the retina that is insensitive to light due to the interruption, where the optic nerve joins the retina, of the normal pattern of light-sensitive rods and cones.
an area or subject about which one is uninformed, prejudiced, or unappreciative:
I confess that operettas are my blind spot.
dead spot (def 1).
Also called dead spot. any part of an auditorium, arena, or the like, in which a person is unable to see or hear satisfactorily.
an area to the side and slightly behind a driver’s field of vision that is not reflected in the vehicle’s rearview mirror.
Contemporary Examples

‘Looking’ Star Jonathan Groff Talks About His Big Gay TV Show. (And Whether We Should Call It That.) Kevin Fallon January 15, 2014
Does Pope Francis Have a Woman Problem? Barbie Latza Nadeau December 19, 2013
Canada’s Subversive Sock Puppet: Ed the Sock Isn’t Afraid to Say Anything Soraya Roberts November 12, 2014

Historical Examples

The Blind Spot Austin Hall
Woodrow Wilson and the World War Charles Seymour
Criminal Psychology Hans Gross
The Blind Spot Austin Hall
Criminal Psychology Hans Gross
The Blind Spot Austin Hall
How it Works Archibald Williams

noun
a small oval-shaped area of the retina in which vision is not experienced. It marks the nonphotosensitive site of entrance into the eyeball of the optic nerve See optic disc
a place or area, as in an auditorium or part of a road, where vision is completely or partially obscured or hearing is difficult or impossible
a subject about which a person is ignorant or prejudiced, or an occupation in which he or she is inefficient
a location within the normal range of a radio transmitter with weak reception
n.

blind spot
(blīnd)
The small region of the retina where fibers of the optic nerve emerge from the eyeball. The blind spot has no rods or cones, so no light or visual image can be transmitted.

Note: In a general sense, the term is used to refer to an inability to see things that might be obvious to another observer: “He has a blind spot as far as his daughter’s behavior is concerned.”

Subject about which one is ignorant or biased. For example, The boss has a blind spot about Henry; he wouldn’t fire him for anything, or Dad has a blind spot about opera; he can’t see anything good about it. This term uses blind in the sense of “covered or hidden from sight.” It has two literal meanings: an insensitive part of the retina and an area outside one’s field of vision. The phrase has largely replaced blind side, which survives mainly in the verb to blindside, meaning “to hit someone on an unguarded side” and “to deal an unexpected blow.” [ Mid-1800s ]