One way to picture it: the eyes are open but no light gets through. The world is still there — the table, the people, the traffic — it just isn't there for these eyes. Nearly every later meaning replays that one situation: something is present, but it never reaches the person.
From the word’s history
Just blind + -ness: the state of not seeing, turned into a noun. Because the suffix only names a state, any kind of not-seeing can slot in — which is why 'blindness to danger' sounds as natural as a medical term.
payload 記的是 blind 加上 -ness，也就是「看不見」這個狀態被名詞化。這個構詞方式本身就說明了它的用法範圍：任何一種「看不見的狀態」都可以套進來，不管擋住的是眼睛還是別的東西——所以英語能自然地說 blindness to danger，就像說一種病一樣說一個人的心理狀態。
payload 提供的詞源說明（Middle English blyndnes < Old English blindnes = blind + -ness，Wiktionary 條目）
登入就可以看每一支怎麼連回核心畫面。
原始詞典資料3 筆記錄
以下是外部詞典記錄的用法，摘錄並精簡格式，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
blindnessnoun/ˈblaɪndnəs/
- 1
The condition of being blind; unable to see.
- DHPG […] is effective in fighting Cytomegalovirus (CMV), a common virus which, for PWAs, can cause CMV retinitis — a condition which can lead to blindness within weeks.
- 2
Want of intellectual or moral discernment; mental darkness; ignorance, heedlessness.
- A tormenting hunger shuddered through her and she wished she could put aside the power. Oh, to be as others were — blind in that safest of all blindnesses, living only the hypnoidal half-life into which birth-shock precipitated most humans.
- 3
obsoleteconcealment
摘錄自 英文維基詞典 English Wiktionary，已精簡格式；依 CC BY-SA 4.0 授權使用，改動後的內容同樣以此授權提供。