盲点
もうてん · mouten · JLPT N1 · noun
blind spot
👁️ 盲 = blind, 点 = spot: a spot you can't see through, like the blind spot in your eye
Where the optic nerve leaves the retina there are no light receptors, so each eye has a real gap in its view. Your brain fills it in, so you rarely notice it.
点 — fire radical 灬 + 占 (zhān, phonetic)
Originally written 點, a semantic-phonetic compound: 黑 (black) gave the meaning 'small black mark or dot' while 占 supplied the sound. It first referred to ink spots, then extended to 'point, drop, a little,' and verbs like 'to mark' or 'to light (a fire),' reflected in the simplified form's 灬 (fire) component.