1864, "spot within one's range of vision where yet one cannot see." Of flaws in the eye, from 1872; figurative sense in use by 1907.
blind spot n.
See optic disk.
The area of blindness in the visual field corresponding to the optic disk. Also called physiologic scotoma, punctum cecum.
An area or facet of one's personality of which one remains ignorant or fails to gain understanding. Also called mental scotoma, scotoma.
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.”